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diff --git a/src/main/java/org/apache/commons/lang3/ArrayUtils.java b/src/main/java/org/apache/commons/lang3/ArrayUtils.java new file mode 100644 index 000000000..95bf83964 --- /dev/null +++ b/src/main/java/org/apache/commons/lang3/ArrayUtils.java @@ -0,0 +1,9646 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.commons.lang3; + +import java.lang.reflect.Array; +import java.lang.reflect.Field; +import java.lang.reflect.Method; +import java.lang.reflect.Type; +import java.util.Arrays; +import java.util.BitSet; +import java.util.Comparator; +import java.util.Date; +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; +import java.util.Random; +import java.util.concurrent.ThreadLocalRandom; +import java.util.function.IntFunction; +import java.util.function.Supplier; + +import org.apache.commons.lang3.builder.EqualsBuilder; +import org.apache.commons.lang3.builder.HashCodeBuilder; +import org.apache.commons.lang3.builder.ToStringBuilder; +import org.apache.commons.lang3.builder.ToStringStyle; +import org.apache.commons.lang3.math.NumberUtils; +import org.apache.commons.lang3.mutable.MutableInt; +import org.apache.commons.lang3.stream.Streams; + +/** + * Operations on arrays, primitive arrays (like {@code int[]}) and + * primitive wrapper arrays (like {@code Integer[]}). + * <p> + * This class tries to handle {@code null} input gracefully. + * An exception will not be thrown for a {@code null} + * array input. However, an Object array that contains a {@code null} + * element may throw an exception. Each method documents its behavior. + * </p> + * <p> + * #ThreadSafe# + * </p> + * @since 2.0 + */ +public class ArrayUtils { + + /** + * An empty immutable {@code boolean} array. + */ + public static final boolean[] EMPTY_BOOLEAN_ARRAY = {}; + + /** + * An empty immutable {@link Boolean} array. + */ + public static final Boolean[] EMPTY_BOOLEAN_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@code byte} array. + */ + public static final byte[] EMPTY_BYTE_ARRAY = {}; + + /** + * An empty immutable {@link Byte} array. + */ + public static final Byte[] EMPTY_BYTE_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@code char} array. + */ + public static final char[] EMPTY_CHAR_ARRAY = {}; + + /** + * An empty immutable {@link Character} array. + */ + public static final Character[] EMPTY_CHARACTER_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@link Class} array. + */ + public static final Class<?>[] EMPTY_CLASS_ARRAY = {}; + + /** + * An empty immutable {@code double} array. + */ + public static final double[] EMPTY_DOUBLE_ARRAY = {}; + + /** + * An empty immutable {@link Double} array. + */ + public static final Double[] EMPTY_DOUBLE_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@link Field} array. + * + * @since 3.10 + */ + public static final Field[] EMPTY_FIELD_ARRAY = {}; + + /** + * An empty immutable {@code float} array. + */ + public static final float[] EMPTY_FLOAT_ARRAY = {}; + + /** + * An empty immutable {@link Float} array. + */ + public static final Float[] EMPTY_FLOAT_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@code int} array. + */ + public static final int[] EMPTY_INT_ARRAY = {}; + + /** + * An empty immutable {@link Integer} array. + */ + public static final Integer[] EMPTY_INTEGER_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@code long} array. + */ + public static final long[] EMPTY_LONG_ARRAY = {}; + + /** + * An empty immutable {@link Long} array. + */ + public static final Long[] EMPTY_LONG_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@link Method} array. + * + * @since 3.10 + */ + public static final Method[] EMPTY_METHOD_ARRAY = {}; + + /** + * An empty immutable {@link Object} array. + */ + public static final Object[] EMPTY_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@code short} array. + */ + public static final short[] EMPTY_SHORT_ARRAY = {}; + + /** + * An empty immutable {@link Short} array. + */ + public static final Short[] EMPTY_SHORT_OBJECT_ARRAY = {}; + + /** + * An empty immutable {@link String} array. + */ + public static final String[] EMPTY_STRING_ARRAY = {}; + + /** + * An empty immutable {@link Throwable} array. + * + * @since 3.10 + */ + public static final Throwable[] EMPTY_THROWABLE_ARRAY = {}; + + /** + * An empty immutable {@link Type} array. + * + * @since 3.10 + */ + public static final Type[] EMPTY_TYPE_ARRAY = {}; + + /** + * The index value when an element is not found in a list or array: {@code -1}. + * This value is returned by methods in this class and can also be used in comparisons with values returned by + * various method from {@link java.util.List}. + */ + public static final int INDEX_NOT_FOUND = -1; + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, true) = [true] + * ArrayUtils.add([true], false) = [true, false] + * ArrayUtils.add([true, false], true) = [true, false, true] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static boolean[] add(final boolean[] array, final boolean element) { + final boolean[] newArray = (boolean[]) copyArrayGrow1(array, Boolean.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0, true) = [true] + * ArrayUtils.add([true], 0, false) = [false, true] + * ArrayUtils.add([false], 1, true) = [false, true] + * ArrayUtils.add([true, false], 1, true) = [true, true, false] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, boolean[], boolean...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static boolean[] add(final boolean[] array, final int index, final boolean element) { + return (boolean[]) add(array, index, Boolean.valueOf(element), Boolean.TYPE); + } + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0) = [0] + * ArrayUtils.add([1], 0) = [1, 0] + * ArrayUtils.add([1, 0], 1) = [1, 0, 1] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static byte[] add(final byte[] array, final byte element) { + final byte[] newArray = (byte[]) copyArrayGrow1(array, Byte.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add([1], 0, 2) = [2, 1] + * ArrayUtils.add([2, 6], 2, 3) = [2, 6, 3] + * ArrayUtils.add([2, 6], 0, 1) = [1, 2, 6] + * ArrayUtils.add([2, 6, 3], 2, 1) = [2, 6, 1, 3] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, byte[], byte...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static byte[] add(final byte[] array, final int index, final byte element) { + return (byte[]) add(array, index, Byte.valueOf(element), Byte.TYPE); + } + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, '0') = ['0'] + * ArrayUtils.add(['1'], '0') = ['1', '0'] + * ArrayUtils.add(['1', '0'], '1') = ['1', '0', '1'] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static char[] add(final char[] array, final char element) { + final char[] newArray = (char[]) copyArrayGrow1(array, Character.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0, 'a') = ['a'] + * ArrayUtils.add(['a'], 0, 'b') = ['b', 'a'] + * ArrayUtils.add(['a', 'b'], 0, 'c') = ['c', 'a', 'b'] + * ArrayUtils.add(['a', 'b'], 1, 'k') = ['a', 'k', 'b'] + * ArrayUtils.add(['a', 'b', 'c'], 1, 't') = ['a', 't', 'b', 'c'] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, char[], char...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static char[] add(final char[] array, final int index, final char element) { + return (char[]) add(array, index, Character.valueOf(element), Character.TYPE); + } + + /** + * Copies the given array and adds the given element at the end of the new array. + * + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0) = [0] + * ArrayUtils.add([1], 0) = [1, 0] + * ArrayUtils.add([1, 0], 1) = [1, 0, 1] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static double[] add(final double[] array, final double element) { + final double[] newArray = (double[]) copyArrayGrow1(array, Double.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add([1.1], 0, 2.2) = [2.2, 1.1] + * ArrayUtils.add([2.3, 6.4], 2, 10.5) = [2.3, 6.4, 10.5] + * ArrayUtils.add([2.6, 6.7], 0, -4.8) = [-4.8, 2.6, 6.7] + * ArrayUtils.add([2.9, 6.0, 0.3], 2, 1.0) = [2.9, 6.0, 1.0, 0.3] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, double[], double...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static double[] add(final double[] array, final int index, final double element) { + return (double[]) add(array, index, Double.valueOf(element), Double.TYPE); + } + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0) = [0] + * ArrayUtils.add([1], 0) = [1, 0] + * ArrayUtils.add([1, 0], 1) = [1, 0, 1] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static float[] add(final float[] array, final float element) { + final float[] newArray = (float[]) copyArrayGrow1(array, Float.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add([1.1f], 0, 2.2f) = [2.2f, 1.1f] + * ArrayUtils.add([2.3f, 6.4f], 2, 10.5f) = [2.3f, 6.4f, 10.5f] + * ArrayUtils.add([2.6f, 6.7f], 0, -4.8f) = [-4.8f, 2.6f, 6.7f] + * ArrayUtils.add([2.9f, 6.0f, 0.3f], 2, 1.0f) = [2.9f, 6.0f, 1.0f, 0.3f] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, float[], float...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static float[] add(final float[] array, final int index, final float element) { + return (float[]) add(array, index, Float.valueOf(element), Float.TYPE); + } + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0) = [0] + * ArrayUtils.add([1], 0) = [1, 0] + * ArrayUtils.add([1, 0], 1) = [1, 0, 1] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static int[] add(final int[] array, final int element) { + final int[] newArray = (int[]) copyArrayGrow1(array, Integer.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add([1], 0, 2) = [2, 1] + * ArrayUtils.add([2, 6], 2, 10) = [2, 6, 10] + * ArrayUtils.add([2, 6], 0, -4) = [-4, 2, 6] + * ArrayUtils.add([2, 6, 3], 2, 1) = [2, 6, 1, 3] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, int[], int...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static int[] add(final int[] array, final int index, final int element) { + return (int[]) add(array, index, Integer.valueOf(element), Integer.TYPE); + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add([1L], 0, 2L) = [2L, 1L] + * ArrayUtils.add([2L, 6L], 2, 10L) = [2L, 6L, 10L] + * ArrayUtils.add([2L, 6L], 0, -4L) = [-4L, 2L, 6L] + * ArrayUtils.add([2L, 6L, 3L], 2, 1L) = [2L, 6L, 1L, 3L] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, long[], long...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static long[] add(final long[] array, final int index, final long element) { + return (long[]) add(array, index, Long.valueOf(element), Long.TYPE); + } + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0) = [0] + * ArrayUtils.add([1], 0) = [1, 0] + * ArrayUtils.add([1, 0], 1) = [1, 0, 1] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static long[] add(final long[] array, final long element) { + final long[] newArray = (long[]) copyArrayGrow1(array, Long.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Underlying implementation of add(array, index, element) methods. + * The last parameter is the class, which may not equal element.getClass + * for primitives. + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @param clss the type of the element being added + * @return A new array containing the existing elements and the new element + */ + private static Object add(final Object array, final int index, final Object element, final Class<?> clss) { + if (array == null) { + if (index != 0) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: 0"); + } + final Object joinedArray = Array.newInstance(clss, 1); + Array.set(joinedArray, 0, element); + return joinedArray; + } + final int length = Array.getLength(array); + if (index > length || index < 0) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length); + } + final Object result = Array.newInstance(clss, length + 1); + System.arraycopy(array, 0, result, 0, index); + Array.set(result, index, element); + if (index < length) { + System.arraycopy(array, index, result, index + 1, length - index); + } + return result; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add([1], 0, 2) = [2, 1] + * ArrayUtils.add([2, 6], 2, 10) = [2, 6, 10] + * ArrayUtils.add([2, 6], 0, -4) = [-4, 2, 6] + * ArrayUtils.add([2, 6, 3], 2, 1) = [2, 6, 1, 3] + * </pre> + * + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index > array.length). + * @deprecated this method has been superseded by {@link #insert(int, short[], short...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static short[] add(final short[] array, final int index, final short element) { + return (short[]) add(array, index, Short.valueOf(element), Short.TYPE); + } + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0) = [0] + * ArrayUtils.add([1], 0) = [1, 0] + * ArrayUtils.add([1, 0], 1) = [1, 0, 1] + * </pre> + * + * @param array the array to copy and add the element to, may be {@code null} + * @param element the object to add at the last index of the new array + * @return A new array containing the existing elements plus the new element + * @since 2.1 + */ + public static short[] add(final short[] array, final short element) { + final short[] newArray = (short[]) copyArrayGrow1(array, Short.TYPE); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Inserts the specified element at the specified position in the array. + * Shifts the element currently at that position (if any) and any subsequent + * elements to the right (adds one to their indices). + * <p> + * This method returns a new array with the same elements of the input + * array plus the given element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element. + * </p> + * <pre> + * ArrayUtils.add(null, 0, null) = IllegalArgumentException + * ArrayUtils.add(null, 0, "a") = ["a"] + * ArrayUtils.add(["a"], 1, null) = ["a", null] + * ArrayUtils.add(["a"], 1, "b") = ["a", "b"] + * ArrayUtils.add(["a", "b"], 3, "c") = ["a", "b", "c"] + * </pre> + * + * @param <T> the component type of the array + * @param array the array to add the element to, may be {@code null} + * @param index the position of the new object + * @param element the object to add + * @return A new array containing the existing elements and the new element + * @throws IndexOutOfBoundsException if the index is out of range (index < 0 || index > array.length). + * @throws IllegalArgumentException if both array and element are null + * @deprecated this method has been superseded by {@link #insert(int, Object[], Object...) insert(int, T[], T...)} and + * may be removed in a future release. Please note the handling of {@code null} input arrays differs + * in the new method: inserting {@code X} into a {@code null} array results in {@code null} not {@code X}. + */ + @Deprecated + public static <T> T[] add(final T[] array, final int index, final T element) { + final Class<T> clss; + if (array != null) { + clss = getComponentType(array); + } else if (element != null) { + clss = ObjectUtils.getClass(element); + } else { + throw new IllegalArgumentException("Array and element cannot both be null"); + } + return (T[]) add(array, index, element, clss); + } + + + /** + * Copies the given array and adds the given element at the end of the new array. + * <p> + * The new array contains the same elements of the input + * array plus the given element in the last position. The component type of + * the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned + * whose component type is the same as the element, unless the element itself is null, + * in which case the return type is Object[] + * </p> + * <pre> + * ArrayUtils.add(null, null) = IllegalArgumentException + * ArrayUtils.add(null, "a") = ["a"] + * ArrayUtils.add(["a"], null) = ["a", null] + * ArrayUtils.add(["a"], "b") = ["a", "b"] + * ArrayUtils.add(["a", "b"], "c") = ["a", "b", "c"] + * </pre> + * + * @param <T> the component type of the array + * @param array the array to "add" the element to, may be {@code null} + * @param element the object to add, may be {@code null} + * @return A new array containing the existing elements plus the new element + * The returned array type will be that of the input array (unless null), + * in which case it will have the same type as the element. + * If both are null, an IllegalArgumentException is thrown + * @since 2.1 + * @throws IllegalArgumentException if both arguments are null + */ + public static <T> T[] add(final T[] array, final T element) { + final Class<?> type; + if (array != null) { + type = array.getClass().getComponentType(); + } else if (element != null) { + type = element.getClass(); + } else { + throw new IllegalArgumentException("Arguments cannot both be null"); + } + @SuppressWarnings("unchecked") // type must be T + final + T[] newArray = (T[]) copyArrayGrow1(array, type); + newArray[newArray.length - 1] = element; + return newArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new boolean[] array. + * @since 2.1 + */ + public static boolean[] addAll(final boolean[] array1, final boolean... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final boolean[] joinedArray = new boolean[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new byte[] array. + * @since 2.1 + */ + public static byte[] addAll(final byte[] array1, final byte... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final byte[] joinedArray = new byte[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new char[] array. + * @since 2.1 + */ + public static char[] addAll(final char[] array1, final char... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final char[] joinedArray = new char[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new double[] array. + * @since 2.1 + */ + public static double[] addAll(final double[] array1, final double... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final double[] joinedArray = new double[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new float[] array. + * @since 2.1 + */ + public static float[] addAll(final float[] array1, final float... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final float[] joinedArray = new float[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new int[] array. + * @since 2.1 + */ + public static int[] addAll(final int[] array1, final int... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final int[] joinedArray = new int[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new long[] array. + * @since 2.1 + */ + public static long[] addAll(final long[] array1, final long... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final long[] joinedArray = new long[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * </pre> + * + * @param array1 the first array whose elements are added to the new array. + * @param array2 the second array whose elements are added to the new array. + * @return The new short[] array. + * @since 2.1 + */ + public static short[] addAll(final short[] array1, final short... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final short[] joinedArray = new short[array1.length + array2.length]; + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + return joinedArray; + } + + /** + * Adds all the elements of the given arrays into a new array. + * <p> + * The new array contains all of the element of {@code array1} followed + * by all of the elements {@code array2}. When an array is returned, it is always + * a new array. + * </p> + * <pre> + * ArrayUtils.addAll(null, null) = null + * ArrayUtils.addAll(array1, null) = cloned copy of array1 + * ArrayUtils.addAll(null, array2) = cloned copy of array2 + * ArrayUtils.addAll([], []) = [] + * ArrayUtils.addAll([null], [null]) = [null, null] + * ArrayUtils.addAll(["a", "b", "c"], ["1", "2", "3"]) = ["a", "b", "c", "1", "2", "3"] + * </pre> + * + * @param <T> the component type of the array + * @param array1 the first array whose elements are added to the new array, may be {@code null} + * @param array2 the second array whose elements are added to the new array, may be {@code null} + * @return The new array, {@code null} if both arrays are {@code null}. + * The type of the new array is the type of the first array, + * unless the first array is null, in which case the type is the same as the second array. + * @since 2.1 + * @throws IllegalArgumentException if the array types are incompatible + */ + public static <T> T[] addAll(final T[] array1, @SuppressWarnings("unchecked") final T... array2) { + if (array1 == null) { + return clone(array2); + } + if (array2 == null) { + return clone(array1); + } + final Class<T> type1 = getComponentType(array1); + final T[] joinedArray = newInstance(type1, array1.length + array2.length); + System.arraycopy(array1, 0, joinedArray, 0, array1.length); + try { + System.arraycopy(array2, 0, joinedArray, array1.length, array2.length); + } catch (final ArrayStoreException ase) { + // Check if problem was due to incompatible types + /* + * We do this here, rather than before the copy because: + * - it would be a wasted check most of the time + * - safer, in case check turns out to be too strict + */ + final Class<?> type2 = array2.getClass().getComponentType(); + if (!type1.isAssignableFrom(type2)) { + throw new IllegalArgumentException("Cannot store " + type2.getName() + " in an array of " + + type1.getName(), ase); + } + throw ase; // No, so rethrow original + } + return joinedArray; + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, true) = [true] + * ArrayUtils.addFirst([true], false) = [false, true] + * ArrayUtils.addFirst([true, false], true) = [true, true, false] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static boolean[] addFirst(final boolean[] array, final boolean element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, 1) = [1] + * ArrayUtils.addFirst([1], 0) = [0, 1] + * ArrayUtils.addFirst([1, 0], 1) = [1, 1, 0] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static byte[] addFirst(final byte[] array, final byte element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, '1') = ['1'] + * ArrayUtils.addFirst(['1'], '0') = ['0', '1'] + * ArrayUtils.addFirst(['1', '0'], '1') = ['1', '1', '0'] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static char[] addFirst(final char[] array, final char element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, 1) = [1] + * ArrayUtils.addFirst([1], 0) = [0, 1] + * ArrayUtils.addFirst([1, 0], 1) = [1, 1, 0] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static double[] addFirst(final double[] array, final double element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, 1) = [1] + * ArrayUtils.addFirst([1], 0) = [0, 1] + * ArrayUtils.addFirst([1, 0], 1) = [1, 1, 0] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static float[] addFirst(final float[] array, final float element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, 1) = [1] + * ArrayUtils.addFirst([1], 0) = [0, 1] + * ArrayUtils.addFirst([1, 0], 1) = [1, 1, 0] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static int[] addFirst(final int[] array, final int element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, 1) = [1] + * ArrayUtils.addFirst([1], 0) = [0, 1] + * ArrayUtils.addFirst([1, 0], 1) = [1, 1, 0] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static long[] addFirst(final long[] array, final long element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element. + * </p> + * <pre> + * ArrayUtils.addFirst(null, 1) = [1] + * ArrayUtils.addFirst([1], 0) = [0, 1] + * ArrayUtils.addFirst([1, 0], 1) = [1, 1, 0] + * </pre> + * + * @param array the array to "add" the element to, may be {@code null}. + * @param element the object to add. + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. + * @since 3.10 + */ + public static short[] addFirst(final short[] array, final short element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Copies the given array and adds the given element at the beginning of the new array. + * <p> + * The new array contains the same elements of the input array plus the given element in the first position. The + * component type of the new array is the same as that of the input array. + * </p> + * <p> + * If the input array is {@code null}, a new one element array is returned whose component type is the same as the + * element, unless the element itself is null, in which case the return type is Object[] + * </p> + * <pre> + * ArrayUtils.addFirst(null, null) = IllegalArgumentException + * ArrayUtils.addFirst(null, "a") = ["a"] + * ArrayUtils.addFirst(["a"], null) = [null, "a"] + * ArrayUtils.addFirst(["a"], "b") = ["b", "a"] + * ArrayUtils.addFirst(["a", "b"], "c") = ["c", "a", "b"] + * </pre> + * + * @param <T> the component type of the array + * @param array the array to "add" the element to, may be {@code null} + * @param element the object to add, may be {@code null} + * @return A new array containing the existing elements plus the new element The returned array type will be that of + * the input array (unless null), in which case it will have the same type as the element. If both are null, + * an IllegalArgumentException is thrown + * @since 3.10 + * @throws IllegalArgumentException if both arguments are null + */ + public static <T> T[] addFirst(final T[] array, final T element) { + return array == null ? add(array, element) : insert(0, array, element); + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static boolean[] clone(final boolean[] array) { + return array != null ? array.clone() : null; + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static byte[] clone(final byte[] array) { + return array != null ? array.clone() : null; + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static char[] clone(final char[] array) { + return array != null ? array.clone() : null; + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static double[] clone(final double[] array) { + return array != null ? array.clone() : null; + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static float[] clone(final float[] array) { + return array != null ? array.clone() : null; + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static int[] clone(final int[] array) { + return array != null ? array.clone() : null; + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static long[] clone(final long[] array) { + return array != null ? array.clone() : null; + } + + /** + * Clones an array returning a typecast result and handling + * {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the array to clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static short[] clone(final short[] array) { + return array != null ? array.clone() : null; + } + + /** + * Shallow clones an array returning a typecast result and handling + * {@code null}. + * <p> + * The objects in the array are not cloned, thus there is no special + * handling for multi-dimensional arrays. + * </p> + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param <T> the component type of the array + * @param array the array to shallow clone, may be {@code null} + * @return the cloned array, {@code null} if {@code null} input + */ + public static <T> T[] clone(final T[] array) { + return array != null ? array.clone() : null; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final boolean[] array, final boolean valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final byte[] array, final byte valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + * @since 2.1 + */ + public static boolean contains(final char[] array, final char valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final double[] array, final double valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if a value falling within the given tolerance is in the + * given array. If the array contains a value within the inclusive range + * defined by (value - tolerance) to (value + tolerance). + * <p> + * The method returns {@code false} if a {@code null} array + * is passed in. + * </p> + * + * @param array the array to search + * @param valueToFind the value to find + * @param tolerance the array contains the tolerance of the search + * @return true if value falling within tolerance is in array + */ + public static boolean contains(final double[] array, final double valueToFind, final double tolerance) { + return indexOf(array, valueToFind, 0, tolerance) != INDEX_NOT_FOUND; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final float[] array, final float valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final int[] array, final int valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final long[] array, final long valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if the object is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param objectToFind the object to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final Object[] array, final Object objectToFind) { + return indexOf(array, objectToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if the value is in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param valueToFind the value to find + * @return {@code true} if the array contains the object + */ + public static boolean contains(final short[] array, final short valueToFind) { + return indexOf(array, valueToFind) != INDEX_NOT_FOUND; + } + + /** + * Checks if any of the objects are in the given array. + * <p> + * The method returns {@code false} if a {@code null} array is passed in. + * </p> + * + * @param array the array to search through + * @param objectsToFind any of the objects to find + * @return {@code true} if the array contains any of the objects + * @since 3.13.0 + */ + public static boolean containsAny(final Object[] array, final Object... objectsToFind) { + return Streams.of(objectsToFind).anyMatch(e -> contains(array, e)); + } + + /** + * Returns a copy of the given array of size 1 greater than the argument. + * The last value of the array is left to the default value. + * + * @param array The array to copy, must not be {@code null}. + * @param newArrayComponentType If {@code array} is {@code null}, create a + * size 1 array of this type. + * @return A new copy of the array of size 1 greater than the input. + */ + private static Object copyArrayGrow1(final Object array, final Class<?> newArrayComponentType) { + if (array != null) { + final int arrayLength = Array.getLength(array); + final Object newArray = Array.newInstance(array.getClass().getComponentType(), arrayLength + 1); + System.arraycopy(array, 0, newArray, 0, arrayLength); + return newArray; + } + return Array.newInstance(newArrayComponentType, 1); + } + + /** + * Gets the nTh element of an array or null if the index is out of bounds or the array is null. + * + * @param <T> The type of array elements. + * @param array The array to index. + * @param index The index + * @return the nTh element of an array or null if the index is out of bounds or the array is null. + * @since 3.11 + */ + public static <T> T get(final T[] array, final int index) { + return get(array, index, null); + } + + /** + * Gets the nTh element of an array or a default value if the index is out of bounds. + * + * @param <T> The type of array elements. + * @param array The array to index. + * @param index The index + * @param defaultValue The return value of the given index is out of bounds. + * @return the nTh element of an array or a default value if the index is out of bounds. + * @since 3.11 + */ + public static <T> T get(final T[] array, final int index, final T defaultValue) { + return isArrayIndexValid(array, index) ? array[index] : defaultValue; + } + + /** + * Gets an array's component type. + * + * @param <T> The array type. + * @param array The array. + * @return The component type. + * @since 3.13.0 + */ + public static <T> Class<T> getComponentType(final T[] array) { + return ClassUtils.getComponentType(ObjectUtils.getClass(array)); + } + + /** + * Returns the length of the specified array. + * This method can deal with {@link Object} arrays and with primitive arrays. + * <p> + * If the input array is {@code null}, {@code 0} is returned. + * </p> + * <pre> + * ArrayUtils.getLength(null) = 0 + * ArrayUtils.getLength([]) = 0 + * ArrayUtils.getLength([null]) = 1 + * ArrayUtils.getLength([true, false]) = 2 + * ArrayUtils.getLength([1, 2, 3]) = 3 + * ArrayUtils.getLength(["a", "b", "c"]) = 3 + * </pre> + * + * @param array the array to retrieve the length from, may be null + * @return The length of the array, or {@code 0} if the array is {@code null} + * @throws IllegalArgumentException if the object argument is not an array. + * @since 2.1 + */ + public static int getLength(final Object array) { + return array != null ? Array.getLength(array) : 0; + } + + /** + * Get a hash code for an array handling multidimensional arrays correctly. + * <p> + * Multi-dimensional primitive arrays are also handled correctly by this method. + * </p> + * + * @param array the array to get a hash code for, {@code null} returns zero + * @return a hash code for the array + */ + public static int hashCode(final Object array) { + return new HashCodeBuilder().append(array).toHashCode(); + } + + /** + * Finds the indices of the given value in the array. + * <p> + * This method returns an empty BitSet for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final boolean[] array, final boolean valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * <p> + * This method returns an empty BitSet for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} + * array input + * @since 3.10 + */ + public static BitSet indexesOf(final boolean[] array, final boolean valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final byte[] array, final byte valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final byte[] array, final byte valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final char[] array, final char valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final char[] array, final char valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array. + * + * <p>This method returns empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final double[] array, final double valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value within a given tolerance in the array. + * + * <p> + * This method will return all the indices of the value which fall between the region + * defined by valueToFind - tolerance and valueToFind + tolerance, each time between the nearest integers. + * </p> + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param tolerance tolerance of the search + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final double[] array, final double valueToFind, final double tolerance) { + return indexesOf(array, valueToFind, 0, tolerance); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final double[] array, final double valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p> + * This method will return the indices of the values which fall between the region + * defined by valueToFind - tolerance and valueToFind + tolerance, between the nearest integers. + * </p> + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @param tolerance tolerance of the search + * @return a BitSet of the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex, tolerance); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final float[] array, final float valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final float[] array, final float valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final int[] array, final int valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final int[] array, final int valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final long[] array, final long valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final long[] array, final long valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given object in the array. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param objectToFind the object to find, may be {@code null} + * @return a BitSet of all the indices of the object within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final Object[] array, final Object objectToFind) { + return indexesOf(array, objectToFind, 0); + } + + /** + * Finds the indices of the given object in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param objectToFind the object to find, may be {@code null} + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the object within the array starting at the index, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final Object[] array, final Object objectToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, objectToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the indices of the given value in the array. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final short[] array, final short valueToFind) { + return indexesOf(array, valueToFind, 0); + } + + /** + * Finds the indices of the given value in the array starting at the given index. + * + * <p>This method returns an empty BitSet for a {@code null} input array.</p> + * + * <p>A negative startIndex is treated as zero. A startIndex larger than the array + * length will return an empty BitSet.</p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return a BitSet of all the indices of the value within the array, + * an empty BitSet if not found or {@code null} array input + * @since 3.10 + */ + public static BitSet indexesOf(final short[] array, final short valueToFind, int startIndex) { + final BitSet bitSet = new BitSet(); + + if (array == null) { + return bitSet; + } + + while (startIndex < array.length) { + startIndex = indexOf(array, valueToFind, startIndex); + + if (startIndex == INDEX_NOT_FOUND) { + break; + } + + bitSet.set(startIndex); + ++startIndex; + } + + return bitSet; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final boolean[] array, final boolean valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} + * array input + */ + public static int indexOf(final boolean[] array, final boolean valueToFind, int startIndex) { + if (isEmpty(array)) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + for (int i = startIndex; i < array.length; i++) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final byte[] array, final byte valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final byte[] array, final byte valueToFind, int startIndex) { + if (array == null) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + for (int i = startIndex; i < array.length; i++) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + * @since 2.1 + */ + public static int indexOf(final char[] array, final char valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + * @since 2.1 + */ + public static int indexOf(final char[] array, final char valueToFind, int startIndex) { + if (array == null) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + for (int i = startIndex; i < array.length; i++) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final double[] array, final double valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value within a given tolerance in the array. + * This method will return the index of the first value which falls between the region + * defined by valueToFind - tolerance and valueToFind + tolerance. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param tolerance tolerance of the search + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final double[] array, final double valueToFind, final double tolerance) { + return indexOf(array, valueToFind, 0, tolerance); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final double[] array, final double valueToFind, int startIndex) { + if (isEmpty(array)) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + final boolean searchNaN = Double.isNaN(valueToFind); + for (int i = startIndex; i < array.length; i++) { + final double element = array[i]; + if (valueToFind == element || searchNaN && Double.isNaN(element)) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array starting at the given index. + * This method will return the index of the first value which falls between the region + * defined by valueToFind - tolerance and valueToFind + tolerance. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @param tolerance tolerance of the search + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) { + if (isEmpty(array)) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + final double min = valueToFind - tolerance; + final double max = valueToFind + tolerance; + for (int i = startIndex; i < array.length; i++) { + if (array[i] >= min && array[i] <= max) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final float[] array, final float valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final float[] array, final float valueToFind, int startIndex) { + if (isEmpty(array)) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + final boolean searchNaN = Float.isNaN(valueToFind); + for (int i = startIndex; i < array.length; i++) { + final float element = array[i]; + if (valueToFind == element || searchNaN && Float.isNaN(element)) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final int[] array, final int valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final int[] array, final int valueToFind, int startIndex) { + if (array == null) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + for (int i = startIndex; i < array.length; i++) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} + * array input + */ + public static int indexOf(final long[] array, final long valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final long[] array, final long valueToFind, int startIndex) { + if (array == null) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + for (int i = startIndex; i < array.length; i++) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given object in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param objectToFind the object to find, may be {@code null} + * @return the index of the object within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final Object[] array, final Object objectToFind) { + return indexOf(array, objectToFind, 0); + } + + /** + * Finds the index of the given object in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param objectToFind the object to find, may be {@code null} + * @param startIndex the index to start searching at + * @return the index of the object within the array starting at the index, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final Object[] array, final Object objectToFind, int startIndex) { + if (array == null) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + if (objectToFind == null) { + for (int i = startIndex; i < array.length; i++) { + if (array[i] == null) { + return i; + } + } + } else { + for (int i = startIndex; i < array.length; i++) { + if (objectToFind.equals(array[i])) { + return i; + } + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the index of the given value in the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final short[] array, final short valueToFind) { + return indexOf(array, valueToFind, 0); + } + + /** + * Finds the index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex is treated as zero. A startIndex larger than the array + * length will return {@link #INDEX_NOT_FOUND} ({@code -1}). + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the index to start searching at + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int indexOf(final short[] array, final short valueToFind, int startIndex) { + if (array == null) { + return INDEX_NOT_FOUND; + } + if (startIndex < 0) { + startIndex = 0; + } + for (int i = startIndex; i < array.length; i++) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static boolean[] insert(final int index, final boolean[] array, final boolean... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final boolean[] result = new boolean[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static byte[] insert(final int index, final byte[] array, final byte... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final byte[] result = new byte[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static char[] insert(final int index, final char[] array, final char... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final char[] result = new char[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static double[] insert(final int index, final double[] array, final double... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final double[] result = new double[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static float[] insert(final int index, final float[] array, final float... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final float[] result = new float[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static int[] insert(final int index, final int[] array, final int... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final int[] result = new int[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static long[] insert(final int index, final long[] array, final long... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final long[] result = new long[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + public static short[] insert(final int index, final short[] array, final short... values) { + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final short[] result = new short[array.length + values.length]; + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Inserts elements into an array at the given index (starting from zero). + * + * <p>When an array is returned, it is always a new array.</p> + * + * <pre> + * ArrayUtils.insert(index, null, null) = null + * ArrayUtils.insert(index, array, null) = cloned copy of 'array' + * ArrayUtils.insert(index, null, values) = null + * </pre> + * + * @param <T> The type of elements in {@code array} and {@code values} + * @param index the position within {@code array} to insert the new values + * @param array the array to insert the values into, may be {@code null} + * @param values the new values to insert, may be {@code null} + * @return The new array. + * @throws IndexOutOfBoundsException if {@code array} is provided + * and either {@code index < 0} or {@code index > array.length} + * @since 3.6 + */ + @SafeVarargs + public static <T> T[] insert(final int index, final T[] array, final T... values) { + /* + * Note on use of @SafeVarargs: + * + * By returning null when 'array' is null, we avoid returning the vararg + * array to the caller. We also avoid relying on the type of the vararg + * array, by inspecting the component type of 'array'. + */ + + if (array == null) { + return null; + } + if (ArrayUtils.isEmpty(values)) { + return clone(array); + } + if (index < 0 || index > array.length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + array.length); + } + + final Class<T> type = getComponentType(array); + final int length = array.length + values.length; + final T[] result = newInstance(type, length); + + System.arraycopy(values, 0, result, index, values.length); + if (index > 0) { + System.arraycopy(array, 0, result, 0, index); + } + if (index < array.length) { + System.arraycopy(array, index, result, index + values.length, array.length - index); + } + return result; + } + + /** + * Checks if an array is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + */ + private static boolean isArrayEmpty(final Object array) { + return getLength(array) == 0; + } + + /** + * Returns whether a given array can safely be accessed at the given index. + * + * <pre> + * ArrayUtils.isArrayIndexValid(null, 0) = false + * ArrayUtils.isArrayIndexValid([], 0) = false + * ArrayUtils.isArrayIndexValid(["a"], 0) = true + * </pre> + * + * @param <T> the component type of the array + * @param array the array to inspect, may be null + * @param index the index of the array to be inspected + * @return Whether the given index is safely-accessible in the given array + * @since 3.8 + */ + public static <T> boolean isArrayIndexValid(final T[] array, final int index) { + return index >= 0 && getLength(array) > index; + } + + /** + * Checks if an array of primitive booleans is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final boolean[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of primitive bytes is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final byte[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of primitive chars is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final char[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of primitive doubles is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final double[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of primitive floats is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final float[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of primitive ints is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final int[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of primitive longs is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final long[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of Objects is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final Object[] array) { + return isArrayEmpty(array); + } + + /** + * Checks if an array of primitive shorts is empty or {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is empty or {@code null} + * @since 2.1 + */ + public static boolean isEmpty(final short[] array) { + return isArrayEmpty(array); + } + + /** + * Compares two arrays, using equals(), handling multi-dimensional arrays + * correctly. + * <p> + * Multi-dimensional primitive arrays are also handled correctly by this method. + * </p> + * + * @param array1 the left-hand array to compare, may be {@code null} + * @param array2 the right-hand array to compare, may be {@code null} + * @return {@code true} if the arrays are equal + * @deprecated this method has been replaced by {@code java.util.Objects.deepEquals(Object, Object)} and will be + * removed from future releases. + */ + @Deprecated + public static boolean isEquals(final Object array1, final Object array2) { + return new EqualsBuilder().append(array1, array2).isEquals(); + } + + /** + * Checks if an array of primitive booleans is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final boolean[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of primitive bytes is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final byte[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of primitive chars is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final char[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of primitive doubles is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final double[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of primitive floats is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final float[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of primitive ints is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final int[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of primitive longs is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final long[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of primitive shorts is not empty and not {@code null}. + * + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static boolean isNotEmpty(final short[] array) { + return !isEmpty(array); + } + + /** + * Checks if an array of Objects is not empty and not {@code null}. + * + * @param <T> the component type of the array + * @param array the array to test + * @return {@code true} if the array is not empty and not {@code null} + * @since 2.5 + */ + public static <T> boolean isNotEmpty(final T[] array) { + return !isEmpty(array); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final boolean[] array1, final boolean[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final byte[] array1, final byte[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final char[] array1, final char[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final double[] array1, final double[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final float[] array1, final float[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final int[] array1, final int[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final long[] array1, final long[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * <p> + * Any multi-dimensional aspects of the arrays are ignored. + * </p> + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + * @since 3.11 + */ + public static boolean isSameLength(final Object array1, final Object array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * <p> + * Any multi-dimensional aspects of the arrays are ignored. + * </p> + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final Object[] array1, final Object[] array2) { + return getLength(array1) == getLength(array2); + } + + + /** + * Checks whether two arrays are the same length, treating + * {@code null} arrays as length {@code 0}. + * + * @param array1 the first array, may be {@code null} + * @param array2 the second array, may be {@code null} + * @return {@code true} if length of arrays matches, treating + * {@code null} as an empty array + */ + public static boolean isSameLength(final short[] array1, final short[] array2) { + return getLength(array1) == getLength(array2); + } + + /** + * Checks whether two arrays are the same type taking into account + * multidimensional arrays. + * + * @param array1 the first array, must not be {@code null} + * @param array2 the second array, must not be {@code null} + * @return {@code true} if type of arrays matches + * @throws IllegalArgumentException if either array is {@code null} + */ + public static boolean isSameType(final Object array1, final Object array2) { + if (array1 == null || array2 == null) { + throw new IllegalArgumentException("The Array must not be null"); + } + return array1.getClass().getName().equals(array2.getClass().getName()); + } + + /** + * This method checks whether the provided array is sorted according to natural ordering + * ({@code false} before {@code true}). + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final boolean[] array) { + if (getLength(array) < 2) { + return true; + } + + boolean previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final boolean current = array[i]; + if (BooleanUtils.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * Checks whether the provided array is sorted according to natural ordering. + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final byte[] array) { + if (getLength(array) < 2) { + return true; + } + + byte previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final byte current = array[i]; + if (NumberUtils.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * Checks whether the provided array is sorted according to natural ordering. + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final char[] array) { + if (getLength(array) < 2) { + return true; + } + + char previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final char current = array[i]; + if (CharUtils.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * This method checks whether the provided array is sorted according to natural ordering. + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final double[] array) { + if (getLength(array) < 2) { + return true; + } + + double previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final double current = array[i]; + if (Double.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * This method checks whether the provided array is sorted according to natural ordering. + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final float[] array) { + if (getLength(array) < 2) { + return true; + } + + float previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final float current = array[i]; + if (Float.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * This method checks whether the provided array is sorted according to natural ordering. + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final int[] array) { + if (getLength(array) < 2) { + return true; + } + + int previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final int current = array[i]; + if (NumberUtils.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * This method checks whether the provided array is sorted according to natural ordering. + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final long[] array) { + if (getLength(array) < 2) { + return true; + } + + long previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final long current = array[i]; + if (NumberUtils.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * This method checks whether the provided array is sorted according to natural ordering. + * + * @param array the array to check + * @return whether the array is sorted according to natural ordering + * @since 3.4 + */ + public static boolean isSorted(final short[] array) { + if (getLength(array) < 2) { + return true; + } + + short previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final short current = array[i]; + if (NumberUtils.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * This method checks whether the provided array is sorted according to the class's + * {@code compareTo} method. + * + * @param array the array to check + * @param <T> the datatype of the array to check, it must implement {@link Comparable} + * @return whether the array is sorted + * @since 3.4 + */ + public static <T extends Comparable<? super T>> boolean isSorted(final T[] array) { + return isSorted(array, Comparable::compareTo); + } + + /** + * This method checks whether the provided array is sorted according to the provided {@link Comparator}. + * + * @param array the array to check + * @param comparator the {@link Comparator} to compare over + * @param <T> the datatype of the array + * @return whether the array is sorted + * @throws NullPointerException if {@code comparator} is {@code null} + * @since 3.4 + */ + public static <T> boolean isSorted(final T[] array, final Comparator<T> comparator) { + Objects.requireNonNull(comparator, "comparator"); + if (getLength(array) < 2) { + return true; + } + T previous = array[0]; + final int n = array.length; + for (int i = 1; i < n; i++) { + final T current = array[i]; + if (comparator.compare(previous, current) > 0) { + return false; + } + + previous = current; + } + return true; + } + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) if + * {@code null} array input. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final boolean[] array, final boolean valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than + * the array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final boolean[] array, final boolean valueToFind, int startIndex) { + if (isEmpty(array) || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final byte[] array, final byte valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final byte[] array, final byte valueToFind, int startIndex) { + if (array == null || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + * @since 2.1 + */ + public static int lastIndexOf(final char[] array, final char valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + * @since 2.1 + */ + public static int lastIndexOf(final char[] array, final char valueToFind, int startIndex) { + if (array == null || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final double[] array, final double valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value within a given tolerance in the array. + * This method will return the index of the last value which falls between the region + * defined by valueToFind - tolerance and valueToFind + tolerance. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to search through for the object, may be {@code null} + * @param valueToFind the value to find + * @param tolerance tolerance of the search + * @return the index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final double[] array, final double valueToFind, final double tolerance) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE, tolerance); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final double[] array, final double valueToFind, int startIndex) { + if (isEmpty(array) || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * This method will return the index of the last value which falls between the region + * defined by valueToFind - tolerance and valueToFind + tolerance. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @param tolerance search for value within plus/minus this amount + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final double[] array, final double valueToFind, int startIndex, final double tolerance) { + if (isEmpty(array) || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + final double min = valueToFind - tolerance; + final double max = valueToFind + tolerance; + for (int i = startIndex; i >= 0; i--) { + if (array[i] >= min && array[i] <= max) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final float[] array, final float valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final float[] array, final float valueToFind, int startIndex) { + if (isEmpty(array) || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final int[] array, final int valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final int[] array, final int valueToFind, int startIndex) { + if (array == null || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final long[] array, final long valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final long[] array, final long valueToFind, int startIndex) { + if (array == null || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given object within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param objectToFind the object to find, may be {@code null} + * @return the last index of the object within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final Object[] array, final Object objectToFind) { + return lastIndexOf(array, objectToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given object in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than + * the array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param objectToFind the object to find, may be {@code null} + * @param startIndex the start index to traverse backwards from + * @return the last index of the object within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final Object[] array, final Object objectToFind, int startIndex) { + if (array == null || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + if (objectToFind == null) { + for (int i = startIndex; i >= 0; i--) { + if (array[i] == null) { + return i; + } + } + } else if (array.getClass().getComponentType().isInstance(objectToFind)) { + for (int i = startIndex; i >= 0; i--) { + if (objectToFind.equals(array[i])) { + return i; + } + } + } + return INDEX_NOT_FOUND; + } + + /** + * Finds the last index of the given value within the array. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * + * @param array the array to traverse backwards looking for the object, may be {@code null} + * @param valueToFind the object to find + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final short[] array, final short valueToFind) { + return lastIndexOf(array, valueToFind, Integer.MAX_VALUE); + } + + /** + * Finds the last index of the given value in the array starting at the given index. + * <p> + * This method returns {@link #INDEX_NOT_FOUND} ({@code -1}) for a {@code null} input array. + * </p> + * <p> + * A negative startIndex will return {@link #INDEX_NOT_FOUND} ({@code -1}). A startIndex larger than the + * array length will search from the end of the array. + * </p> + * + * @param array the array to traverse for looking for the object, may be {@code null} + * @param valueToFind the value to find + * @param startIndex the start index to traverse backwards from + * @return the last index of the value within the array, + * {@link #INDEX_NOT_FOUND} ({@code -1}) if not found or {@code null} array input + */ + public static int lastIndexOf(final short[] array, final short valueToFind, int startIndex) { + if (array == null || startIndex < 0) { + return INDEX_NOT_FOUND; + } + if (startIndex >= array.length) { + startIndex = array.length - 1; + } + for (int i = startIndex; i >= 0; i--) { + if (valueToFind == array[i]) { + return i; + } + } + return INDEX_NOT_FOUND; + } + + /** + * Delegates to {@link Array#newInstance(Class,int)} using generics. + * + * @param <T> The array type. + * @param componentType The array class. + * @param length the array length + * @return The new array. + * @throws NullPointerException if the specified {@code componentType} parameter is null. + * @since 3.13.0 + */ + @SuppressWarnings("unchecked") // OK, because array and values are of type T + public static <T> T[] newInstance(final Class<T> componentType, final int length) { + return (T[]) Array.newInstance(componentType, length); + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static boolean[] nullToEmpty(final boolean[] array) { + return isEmpty(array) ? EMPTY_BOOLEAN_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Boolean[] nullToEmpty(final Boolean[] array) { + return isEmpty(array) ? EMPTY_BOOLEAN_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static byte[] nullToEmpty(final byte[] array) { + return isEmpty(array) ? EMPTY_BYTE_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Byte[] nullToEmpty(final Byte[] array) { + return isEmpty(array) ? EMPTY_BYTE_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static char[] nullToEmpty(final char[] array) { + return isEmpty(array) ? EMPTY_CHAR_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Character[] nullToEmpty(final Character[] array) { + return isEmpty(array) ? EMPTY_CHARACTER_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 3.2 + */ + public static Class<?>[] nullToEmpty(final Class<?>[] array) { + return isEmpty(array) ? EMPTY_CLASS_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static double[] nullToEmpty(final double[] array) { + return isEmpty(array) ? EMPTY_DOUBLE_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Double[] nullToEmpty(final Double[] array) { + return isEmpty(array) ? EMPTY_DOUBLE_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static float[] nullToEmpty(final float[] array) { + return isEmpty(array) ? EMPTY_FLOAT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Float[] nullToEmpty(final Float[] array) { + return isEmpty(array) ? EMPTY_FLOAT_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static int[] nullToEmpty(final int[] array) { + return isEmpty(array) ? EMPTY_INT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Integer[] nullToEmpty(final Integer[] array) { + return isEmpty(array) ? EMPTY_INTEGER_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static long[] nullToEmpty(final long[] array) { + return isEmpty(array) ? EMPTY_LONG_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Long[] nullToEmpty(final Long[] array) { + return isEmpty(array) ? EMPTY_LONG_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Object[] nullToEmpty(final Object[] array) { + return isEmpty(array) ? EMPTY_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static short[] nullToEmpty(final short[] array) { + return isEmpty(array) ? EMPTY_SHORT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static Short[] nullToEmpty(final Short[] array) { + return isEmpty(array) ? EMPTY_SHORT_OBJECT_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * <p> + * As a memory optimizing technique an empty array passed in will be overridden with + * the empty {@code public static} references in this class. + * </p> + * + * @param array the array to check for {@code null} or empty + * @return the same array, {@code public static} empty array if {@code null} or empty input + * @since 2.5 + */ + public static String[] nullToEmpty(final String[] array) { + return isEmpty(array) ? EMPTY_STRING_ARRAY : array; + } + + /** + * Defensive programming technique to change a {@code null} + * reference to an empty one. + * <p> + * This method returns an empty array for a {@code null} input array. + * </p> + * + * @param array the array to check for {@code null} or empty + * @param type the class representation of the desired array + * @param <T> the class type + * @return the same array, {@code public static} empty array if {@code null} + * @throws IllegalArgumentException if the type argument is null + * @since 3.5 + */ + public static <T> T[] nullToEmpty(final T[] array, final Class<T[]> type) { + if (type == null) { + throw new IllegalArgumentException("The type must not be null"); + } + + if (array == null) { + return type.cast(Array.newInstance(type.getComponentType(), 0)); + } + return array; + } + + private static ThreadLocalRandom random() { + return ThreadLocalRandom.current(); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove([true], 0) = [] + * ArrayUtils.remove([true, false], 0) = [false] + * ArrayUtils.remove([true, false], 1) = [true] + * ArrayUtils.remove([true, true, false], 1) = [true, false] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static boolean[] remove(final boolean[] array, final int index) { + return (boolean[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove([1], 0) = [] + * ArrayUtils.remove([1, 0], 0) = [0] + * ArrayUtils.remove([1, 0], 1) = [1] + * ArrayUtils.remove([1, 0, 1], 1) = [1, 1] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static byte[] remove(final byte[] array, final int index) { + return (byte[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove(['a'], 0) = [] + * ArrayUtils.remove(['a', 'b'], 0) = ['b'] + * ArrayUtils.remove(['a', 'b'], 1) = ['a'] + * ArrayUtils.remove(['a', 'b', 'c'], 1) = ['a', 'c'] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static char[] remove(final char[] array, final int index) { + return (char[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove([1.1], 0) = [] + * ArrayUtils.remove([2.5, 6.0], 0) = [6.0] + * ArrayUtils.remove([2.5, 6.0], 1) = [2.5] + * ArrayUtils.remove([2.5, 6.0, 3.8], 1) = [2.5, 3.8] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static double[] remove(final double[] array, final int index) { + return (double[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove([1.1], 0) = [] + * ArrayUtils.remove([2.5, 6.0], 0) = [6.0] + * ArrayUtils.remove([2.5, 6.0], 1) = [2.5] + * ArrayUtils.remove([2.5, 6.0, 3.8], 1) = [2.5, 3.8] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static float[] remove(final float[] array, final int index) { + return (float[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove([1], 0) = [] + * ArrayUtils.remove([2, 6], 0) = [6] + * ArrayUtils.remove([2, 6], 1) = [2] + * ArrayUtils.remove([2, 6, 3], 1) = [2, 3] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static int[] remove(final int[] array, final int index) { + return (int[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove([1], 0) = [] + * ArrayUtils.remove([2, 6], 0) = [6] + * ArrayUtils.remove([2, 6], 1) = [2] + * ArrayUtils.remove([2, 6, 3], 1) = [2, 3] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static long[] remove(final long[] array, final int index) { + return (long[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + private static Object remove(final Object array, final int index) { + final int length = getLength(array); + if (index < 0 || index >= length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length); + } + + final Object result = Array.newInstance(array.getClass().getComponentType(), length - 1); + System.arraycopy(array, 0, result, 0, index); + if (index < length - 1) { + System.arraycopy(array, index + 1, result, index, length - index - 1); + } + + return result; + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove([1], 0) = [] + * ArrayUtils.remove([2, 6], 0) = [6] + * ArrayUtils.remove([2, 6], 1) = [2] + * ArrayUtils.remove([2, 6, 3], 1) = [2, 3] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + public static short[] remove(final short[] array, final int index) { + return (short[]) remove((Object) array, index); + } + + /** + * Removes the element at the specified position from the specified array. + * All subsequent elements are shifted to the left (subtracts one from + * their indices). + * <p> + * This method returns a new array with the same elements of the input + * array except the element on the specified position. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.remove(["a"], 0) = [] + * ArrayUtils.remove(["a", "b"], 0) = ["b"] + * ArrayUtils.remove(["a", "b"], 1) = ["a"] + * ArrayUtils.remove(["a", "b", "c"], 1) = ["a", "c"] + * </pre> + * + * @param <T> the component type of the array + * @param array the array to remove the element from, may not be {@code null} + * @param index the position of the element to be removed + * @return A new array containing the existing elements except the element + * at the specified position. + * @throws IndexOutOfBoundsException if the index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 2.1 + */ + @SuppressWarnings("unchecked") // remove() always creates an array of the same type as its input + public static <T> T[] remove(final T[] array, final int index) { + return (T[]) remove((Object) array, index); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([true, false, true], 0, 2) = [false] + * ArrayUtils.removeAll([true, false, true], 1, 2) = [true] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static boolean[] removeAll(final boolean[] array, final int... indices) { + return (boolean[]) removeAll((Object) array, indices); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([1], 0) = [] + * ArrayUtils.removeAll([2, 6], 0) = [6] + * ArrayUtils.removeAll([2, 6], 0, 1) = [] + * ArrayUtils.removeAll([2, 6, 3], 1, 2) = [2] + * ArrayUtils.removeAll([2, 6, 3], 0, 2) = [6] + * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = [] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static byte[] removeAll(final byte[] array, final int... indices) { + return (byte[]) removeAll((Object) array, indices); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([1], 0) = [] + * ArrayUtils.removeAll([2, 6], 0) = [6] + * ArrayUtils.removeAll([2, 6], 0, 1) = [] + * ArrayUtils.removeAll([2, 6, 3], 1, 2) = [2] + * ArrayUtils.removeAll([2, 6, 3], 0, 2) = [6] + * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = [] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static char[] removeAll(final char[] array, final int... indices) { + return (char[]) removeAll((Object) array, indices); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([1], 0) = [] + * ArrayUtils.removeAll([2, 6], 0) = [6] + * ArrayUtils.removeAll([2, 6], 0, 1) = [] + * ArrayUtils.removeAll([2, 6, 3], 1, 2) = [2] + * ArrayUtils.removeAll([2, 6, 3], 0, 2) = [6] + * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = [] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static double[] removeAll(final double[] array, final int... indices) { + return (double[]) removeAll((Object) array, indices); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([1], 0) = [] + * ArrayUtils.removeAll([2, 6], 0) = [6] + * ArrayUtils.removeAll([2, 6], 0, 1) = [] + * ArrayUtils.removeAll([2, 6, 3], 1, 2) = [2] + * ArrayUtils.removeAll([2, 6, 3], 0, 2) = [6] + * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = [] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static float[] removeAll(final float[] array, final int... indices) { + return (float[]) removeAll((Object) array, indices); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([1], 0) = [] + * ArrayUtils.removeAll([2, 6], 0) = [6] + * ArrayUtils.removeAll([2, 6], 0, 1) = [] + * ArrayUtils.removeAll([2, 6, 3], 1, 2) = [2] + * ArrayUtils.removeAll([2, 6, 3], 0, 2) = [6] + * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = [] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static int[] removeAll(final int[] array, final int... indices) { + return (int[]) removeAll((Object) array, indices); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([1], 0) = [] + * ArrayUtils.removeAll([2, 6], 0) = [6] + * ArrayUtils.removeAll([2, 6], 0, 1) = [] + * ArrayUtils.removeAll([2, 6, 3], 1, 2) = [2] + * ArrayUtils.removeAll([2, 6, 3], 0, 2) = [6] + * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = [] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static long[] removeAll(final long[] array, final int... indices) { + return (long[]) removeAll((Object) array, indices); + } + + /** + * Removes multiple array elements specified by indices. + * + * @param array source + * @param indices to remove + * @return new array of same type minus elements specified by the set bits in {@code indices} + * @since 3.2 + */ + // package protected for access by unit tests + static Object removeAll(final Object array, final BitSet indices) { + if (array == null) { + return null; + } + + final int srcLength = getLength(array); + // No need to check maxIndex here, because method only currently called from removeElements() + // which guarantee to generate only valid bit entries. +// final int maxIndex = indices.length(); +// if (maxIndex > srcLength) { +// throw new IndexOutOfBoundsException("Index: " + (maxIndex-1) + ", Length: " + srcLength); +// } + final int removals = indices.cardinality(); // true bits are items to remove + final Object result = Array.newInstance(array.getClass().getComponentType(), srcLength - removals); + int srcIndex = 0; + int destIndex = 0; + int count; + int set; + while ((set = indices.nextSetBit(srcIndex)) != -1) { + count = set - srcIndex; + if (count > 0) { + System.arraycopy(array, srcIndex, result, destIndex, count); + destIndex += count; + } + srcIndex = indices.nextClearBit(set); + } + count = srcLength - srcIndex; + if (count > 0) { + System.arraycopy(array, srcIndex, result, destIndex, count); + } + return result; + } + + /** + * Removes multiple array elements specified by index. + * + * @param array source + * @param indices to remove + * @return new array of same type minus elements specified by unique values of {@code indices} + * @since 3.0.1 + */ + // package protected for access by unit tests + static Object removeAll(final Object array, final int... indices) { + final int length = getLength(array); + int diff = 0; // number of distinct indexes, i.e. number of entries that will be removed + final int[] clonedIndices = ArraySorter.sort(clone(indices)); + + // identify length of result array + if (isNotEmpty(clonedIndices)) { + int i = clonedIndices.length; + int prevIndex = length; + while (--i >= 0) { + final int index = clonedIndices[i]; + if (index < 0 || index >= length) { + throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length); + } + if (index >= prevIndex) { + continue; + } + diff++; + prevIndex = index; + } + } + + // create result array + final Object result = Array.newInstance(array.getClass().getComponentType(), length - diff); + if (diff < length) { + int end = length; // index just after last copy + int dest = length - diff; // number of entries so far not copied + for (int i = clonedIndices.length - 1; i >= 0; i--) { + final int index = clonedIndices[i]; + if (end - index > 1) { // same as (cp > 0) + final int cp = end - index - 1; + dest -= cp; + System.arraycopy(array, index + 1, result, dest, cp); + // After this copy, we still have room for dest items. + } + end = index; + } + if (end > 0) { + System.arraycopy(array, 0, result, 0, end); + } + } + return result; + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll([1], 0) = [] + * ArrayUtils.removeAll([2, 6], 0) = [6] + * ArrayUtils.removeAll([2, 6], 0, 1) = [] + * ArrayUtils.removeAll([2, 6, 3], 1, 2) = [2] + * ArrayUtils.removeAll([2, 6, 3], 0, 2) = [6] + * ArrayUtils.removeAll([2, 6, 3], 0, 1, 2) = [] + * </pre> + * + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + public static short[] removeAll(final short[] array, final int... indices) { + return (short[]) removeAll((Object) array, indices); + } + + /** + * Removes the elements at the specified positions from the specified array. + * All remaining elements are shifted to the left. + * <p> + * This method returns a new array with the same elements of the input + * array except those at the specified positions. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <p> + * If the input array is {@code null}, an IndexOutOfBoundsException + * will be thrown, because in that case no valid index can be specified. + * </p> + * <pre> + * ArrayUtils.removeAll(["a", "b", "c"], 0, 2) = ["b"] + * ArrayUtils.removeAll(["a", "b", "c"], 1, 2) = ["a"] + * </pre> + * + * @param <T> the component type of the array + * @param array the array to remove the element from, may not be {@code null} + * @param indices the positions of the elements to be removed + * @return A new array containing the existing elements except those + * at the specified positions. + * @throws IndexOutOfBoundsException if any index is out of range + * (index < 0 || index >= array.length), or if the array is {@code null}. + * @since 3.0.1 + */ + @SuppressWarnings("unchecked") // removeAll() always creates an array of the same type as its input + public static <T> T[] removeAll(final T[] array, final int... indices) { + return (T[]) removeAll((Object) array, indices); + } + + /** + * Removes the occurrences of the specified element from the specified boolean array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(boolean[], boolean)} + */ + @Deprecated + public static boolean[] removeAllOccurences(final boolean[] array, final boolean element) { + return (boolean[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified byte array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(byte[], byte)} + */ + @Deprecated + public static byte[] removeAllOccurences(final byte[] array, final byte element) { + return (byte[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified char array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(char[], char)} + */ + @Deprecated + public static char[] removeAllOccurences(final char[] array, final char element) { + return (char[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified double array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(double[], double)} + */ + @Deprecated + public static double[] removeAllOccurences(final double[] array, final double element) { + return (double[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified float array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(float[], float)} + */ + @Deprecated + public static float[] removeAllOccurences(final float[] array, final float element) { + return (float[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified int array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(int[], int)} + */ + @Deprecated + public static int[] removeAllOccurences(final int[] array, final int element) { + return (int[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified long array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(long[], long)} + */ + @Deprecated + public static long[] removeAllOccurences(final long[] array, final long element) { + return (long[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified short array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(short[], short)} + */ + @Deprecated + public static short[] removeAllOccurences(final short[] array, final short element) { + return (short[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param <T> the type of object in the array + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.5 + * @deprecated Use {@link #removeAllOccurrences(Object[], Object)} + */ + @Deprecated + public static <T> T[] removeAllOccurences(final T[] array, final T element) { + return (T[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified boolean array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static boolean[] removeAllOccurrences(final boolean[] array, final boolean element) { + return (boolean[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified byte array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static byte[] removeAllOccurrences(final byte[] array, final byte element) { + return (byte[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified char array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static char[] removeAllOccurrences(final char[] array, final char element) { + return (char[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified double array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static double[] removeAllOccurrences(final double[] array, final double element) { + return (double[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified float array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static float[] removeAllOccurrences(final float[] array, final float element) { + return (float[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified int array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static int[] removeAllOccurrences(final int[] array, final int element) { + return (int[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified long array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static long[] removeAllOccurrences(final long[] array, final long element) { + return (long[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified short array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static short[] removeAllOccurrences(final short[] array, final short element) { + return (short[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the occurrences of the specified element from the specified array. + * <p> + * All subsequent elements are shifted to the left (subtracts one from their indices). + * If the array doesn't contain such an element, no elements are removed from the array. + * {@code null} will be returned if the input array is {@code null}. + * </p> + * + * @param <T> the type of object in the array + * @param element the element to remove + * @param array the input array + * + * @return A new array containing the existing elements except the occurrences of the specified element. + * @since 3.10 + */ + public static <T> T[] removeAllOccurrences(final T[] array, final T element) { + return (T[]) removeAll((Object) array, indexesOf(array, element)); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, true) = null + * ArrayUtils.removeElement([], true) = [] + * ArrayUtils.removeElement([true], false) = [true] + * ArrayUtils.removeElement([true, false], false) = [true] + * ArrayUtils.removeElement([true, false, true], true) = [false, true] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static boolean[] removeElement(final boolean[] array, final boolean element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, 1) = null + * ArrayUtils.removeElement([], 1) = [] + * ArrayUtils.removeElement([1], 0) = [1] + * ArrayUtils.removeElement([1, 0], 0) = [1] + * ArrayUtils.removeElement([1, 0, 1], 1) = [0, 1] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static byte[] removeElement(final byte[] array, final byte element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, 'a') = null + * ArrayUtils.removeElement([], 'a') = [] + * ArrayUtils.removeElement(['a'], 'b') = ['a'] + * ArrayUtils.removeElement(['a', 'b'], 'a') = ['b'] + * ArrayUtils.removeElement(['a', 'b', 'a'], 'a') = ['b', 'a'] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static char[] removeElement(final char[] array, final char element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, 1.1) = null + * ArrayUtils.removeElement([], 1.1) = [] + * ArrayUtils.removeElement([1.1], 1.2) = [1.1] + * ArrayUtils.removeElement([1.1, 2.3], 1.1) = [2.3] + * ArrayUtils.removeElement([1.1, 2.3, 1.1], 1.1) = [2.3, 1.1] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static double[] removeElement(final double[] array, final double element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, 1.1) = null + * ArrayUtils.removeElement([], 1.1) = [] + * ArrayUtils.removeElement([1.1], 1.2) = [1.1] + * ArrayUtils.removeElement([1.1, 2.3], 1.1) = [2.3] + * ArrayUtils.removeElement([1.1, 2.3, 1.1], 1.1) = [2.3, 1.1] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static float[] removeElement(final float[] array, final float element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, 1) = null + * ArrayUtils.removeElement([], 1) = [] + * ArrayUtils.removeElement([1], 2) = [1] + * ArrayUtils.removeElement([1, 3], 1) = [3] + * ArrayUtils.removeElement([1, 3, 1], 1) = [3, 1] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static int[] removeElement(final int[] array, final int element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, 1) = null + * ArrayUtils.removeElement([], 1) = [] + * ArrayUtils.removeElement([1], 2) = [1] + * ArrayUtils.removeElement([1, 3], 1) = [3] + * ArrayUtils.removeElement([1, 3, 1], 1) = [3, 1] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static long[] removeElement(final long[] array, final long element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, 1) = null + * ArrayUtils.removeElement([], 1) = [] + * ArrayUtils.removeElement([1], 2) = [1] + * ArrayUtils.removeElement([1, 3], 1) = [3] + * ArrayUtils.removeElement([1, 3, 1], 1) = [3, 1] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static short[] removeElement(final short[] array, final short element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes the first occurrence of the specified element from the + * specified array. All subsequent elements are shifted to the left + * (subtracts one from their indices). If the array doesn't contain + * such an element, no elements are removed from the array. + * <p> + * This method returns a new array with the same elements of the input + * array except the first occurrence of the specified element. The component + * type of the returned array is always the same as that of the input + * array. + * </p> + * <pre> + * ArrayUtils.removeElement(null, "a") = null + * ArrayUtils.removeElement([], "a") = [] + * ArrayUtils.removeElement(["a"], "b") = ["a"] + * ArrayUtils.removeElement(["a", "b"], "a") = ["b"] + * ArrayUtils.removeElement(["a", "b", "a"], "a") = ["b", "a"] + * </pre> + * + * @param <T> the component type of the array + * @param array the array to remove the element from, may be {@code null} + * @param element the element to be removed + * @return A new array containing the existing elements except the first + * occurrence of the specified element. + * @since 2.1 + */ + public static <T> T[] removeElement(final T[] array, final Object element) { + final int index = indexOf(array, element); + return index == INDEX_NOT_FOUND ? clone(array) : remove(array, index); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, true, false) = null + * ArrayUtils.removeElements([], true, false) = [] + * ArrayUtils.removeElements([true], false, false) = [true] + * ArrayUtils.removeElements([true, false], true, true) = [false] + * ArrayUtils.removeElements([true, false, true], true) = [false, true] + * ArrayUtils.removeElements([true, false, true], true, true) = [false] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static boolean[] removeElements(final boolean[] array, final boolean... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<Boolean, MutableInt> occurrences = new HashMap<>(2); // only two possible values here + for (final boolean v : values) { + final Boolean boxed = Boolean.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final boolean key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (boolean[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, 1, 2) = null + * ArrayUtils.removeElements([], 1, 2) = [] + * ArrayUtils.removeElements([1], 2, 3) = [1] + * ArrayUtils.removeElements([1, 3], 1, 2) = [3] + * ArrayUtils.removeElements([1, 3, 1], 1) = [3, 1] + * ArrayUtils.removeElements([1, 3, 1], 1, 1) = [3] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static byte[] removeElements(final byte[] array, final byte... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final Map<Byte, MutableInt> occurrences = new HashMap<>(values.length); + for (final byte v : values) { + final Byte boxed = Byte.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final byte key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (byte[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, 1, 2) = null + * ArrayUtils.removeElements([], 1, 2) = [] + * ArrayUtils.removeElements([1], 2, 3) = [1] + * ArrayUtils.removeElements([1, 3], 1, 2) = [3] + * ArrayUtils.removeElements([1, 3, 1], 1) = [3, 1] + * ArrayUtils.removeElements([1, 3, 1], 1, 1) = [3] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static char[] removeElements(final char[] array, final char... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<Character, MutableInt> occurrences = new HashMap<>(values.length); + for (final char v : values) { + final Character boxed = Character.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final char key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (char[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, 1, 2) = null + * ArrayUtils.removeElements([], 1, 2) = [] + * ArrayUtils.removeElements([1], 2, 3) = [1] + * ArrayUtils.removeElements([1, 3], 1, 2) = [3] + * ArrayUtils.removeElements([1, 3, 1], 1) = [3, 1] + * ArrayUtils.removeElements([1, 3, 1], 1, 1) = [3] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static double[] removeElements(final double[] array, final double... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<Double, MutableInt> occurrences = new HashMap<>(values.length); + for (final double v : values) { + final Double boxed = Double.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final double key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (double[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, 1, 2) = null + * ArrayUtils.removeElements([], 1, 2) = [] + * ArrayUtils.removeElements([1], 2, 3) = [1] + * ArrayUtils.removeElements([1, 3], 1, 2) = [3] + * ArrayUtils.removeElements([1, 3, 1], 1) = [3, 1] + * ArrayUtils.removeElements([1, 3, 1], 1, 1) = [3] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static float[] removeElements(final float[] array, final float... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<Float, MutableInt> occurrences = new HashMap<>(values.length); + for (final float v : values) { + final Float boxed = Float.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final float key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (float[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, 1, 2) = null + * ArrayUtils.removeElements([], 1, 2) = [] + * ArrayUtils.removeElements([1], 2, 3) = [1] + * ArrayUtils.removeElements([1, 3], 1, 2) = [3] + * ArrayUtils.removeElements([1, 3, 1], 1) = [3, 1] + * ArrayUtils.removeElements([1, 3, 1], 1, 1) = [3] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static int[] removeElements(final int[] array, final int... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<Integer, MutableInt> occurrences = new HashMap<>(values.length); + for (final int v : values) { + final Integer boxed = Integer.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final int key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (int[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, 1, 2) = null + * ArrayUtils.removeElements([], 1, 2) = [] + * ArrayUtils.removeElements([1], 2, 3) = [1] + * ArrayUtils.removeElements([1, 3], 1, 2) = [3] + * ArrayUtils.removeElements([1, 3, 1], 1) = [3, 1] + * ArrayUtils.removeElements([1, 3, 1], 1, 1) = [3] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static long[] removeElements(final long[] array, final long... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<Long, MutableInt> occurrences = new HashMap<>(values.length); + for (final long v : values) { + final Long boxed = Long.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final long key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (long[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, 1, 2) = null + * ArrayUtils.removeElements([], 1, 2) = [] + * ArrayUtils.removeElements([1], 2, 3) = [1] + * ArrayUtils.removeElements([1, 3], 1, 2) = [3] + * ArrayUtils.removeElements([1, 3, 1], 1) = [3, 1] + * ArrayUtils.removeElements([1, 3, 1], 1, 1) = [3] + * </pre> + * + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + public static short[] removeElements(final short[] array, final short... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<Short, MutableInt> occurrences = new HashMap<>(values.length); + for (final short v : values) { + final Short boxed = Short.valueOf(v); + final MutableInt count = occurrences.get(boxed); + if (count == null) { + occurrences.put(boxed, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final short key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + return (short[]) removeAll(array, toRemove); + } + + /** + * Removes occurrences of specified elements, in specified quantities, + * from the specified array. All subsequent elements are shifted left. + * For any element-to-be-removed specified in greater quantities than + * contained in the original array, no change occurs beyond the + * removal of the existing matching items. + * <p> + * This method returns a new array with the same elements of the input + * array except for the earliest-encountered occurrences of the specified + * elements. The component type of the returned array is always the same + * as that of the input array. + * </p> + * <pre> + * ArrayUtils.removeElements(null, "a", "b") = null + * ArrayUtils.removeElements([], "a", "b") = [] + * ArrayUtils.removeElements(["a"], "b", "c") = ["a"] + * ArrayUtils.removeElements(["a", "b"], "a", "c") = ["b"] + * ArrayUtils.removeElements(["a", "b", "a"], "a") = ["b", "a"] + * ArrayUtils.removeElements(["a", "b", "a"], "a", "a") = ["b"] + * </pre> + * + * @param <T> the component type of the array + * @param array the array to remove the element from, may be {@code null} + * @param values the elements to be removed + * @return A new array containing the existing elements except the + * earliest-encountered occurrences of the specified elements. + * @since 3.0.1 + */ + @SafeVarargs + public static <T> T[] removeElements(final T[] array, final T... values) { + if (isEmpty(array) || isEmpty(values)) { + return clone(array); + } + final HashMap<T, MutableInt> occurrences = new HashMap<>(values.length); + for (final T v : values) { + final MutableInt count = occurrences.get(v); + if (count == null) { + occurrences.put(v, new MutableInt(1)); + } else { + count.increment(); + } + } + final BitSet toRemove = new BitSet(); + for (int i = 0; i < array.length; i++) { + final T key = array[i]; + final MutableInt count = occurrences.get(key); + if (count != null) { + if (count.decrementAndGet() == 0) { + occurrences.remove(key); + } + toRemove.set(i); + } + } + @SuppressWarnings("unchecked") // removeAll() always creates an array of the same type as its input + final T[] result = (T[]) removeAll(array, toRemove); + return result; + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final boolean[] array) { + if (array == null) { + return; + } + reverse(array, 0, array.length); + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final boolean[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + boolean tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final byte[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final byte[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + byte tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final char[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final char[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + char tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final double[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final double[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + double tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final float[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final float[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + float tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final int[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final int[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + int tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final long[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final long[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + long tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * There is no special handling for multi-dimensional arrays. + * </p> + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final Object[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Under value (<0) is promoted to 0, over value (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Under value (< start index) results in no + * change. Over value (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final Object[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + Object tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Reverses the order of the given array. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array the array to reverse, may be {@code null} + */ + public static void reverse(final short[] array) { + if (array != null) { + reverse(array, 0, array.length); + } + } + + /** + * Reverses the order of the given array in the given range. + * <p> + * This method does nothing for a {@code null} input array. + * </p> + * + * @param array + * the array to reverse, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are reversed in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @since 3.2 + */ + public static void reverse(final short[] array, final int startIndexInclusive, final int endIndexExclusive) { + if (array == null) { + return; + } + int i = Math.max(startIndexInclusive, 0); + int j = Math.min(array.length, endIndexExclusive) - 1; + short tmp; + while (j > i) { + tmp = array[j]; + array[j] = array[i]; + array[i] = tmp; + j--; + i++; + } + } + + /** + * Sets all elements of the specified array, using the provided generator supplier to compute each element. + * <p> + * If the generator supplier throws an exception, it is relayed to the caller and the array is left in an indeterminate + * state. + * </p> + * + * @param <T> type of elements of the array. + * @param array array to be initialized. + * @param generator a function accepting an index and producing the desired value for that position. + * @return the input array + * @since 3.13.0 + */ + public static <T> T[] setAll(final T[] array, final IntFunction<? extends T> generator) { + if (array != null && generator != null) { + Arrays.setAll(array, generator); + } + return array; + } + + /** + * Sets all elements of the specified array, using the provided generator supplier to compute each element. + * <p> + * If the generator supplier throws an exception, it is relayed to the caller and the array is left in an indeterminate + * state. + * </p> + * + * @param <T> type of elements of the array. + * @param array array to be initialized. + * @param generator a function accepting an index and producing the desired value for that position. + * @return the input array + * @since 3.13.0 + */ + public static <T> T[] setAll(final T[] array, final Supplier<? extends T> generator) { + if (array != null && generator != null) { + for (int i = 0; i < array.length; i++) { + array[i] = generator.get(); + } + } + return array; + } + + /** + * Shifts the order of the given boolean array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final boolean[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given boolean array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final boolean[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given byte array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final byte[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given byte array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final byte[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given char array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final char[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given char array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final char[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given double array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final double[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given double array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final double[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given float array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final float[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given float array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final float[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given int array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final int[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given int array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final int[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given long array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final long[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given long array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final long[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final Object[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final Object[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Shifts the order of the given short array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array the array to shift, may be {@code null} + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final short[] array, final int offset) { + if (array != null) { + shift(array, 0, array.length, offset); + } + } + + /** + * Shifts the order of a series of elements in the given short array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for {@code null} or empty input arrays.</p> + * + * @param array + * the array to shift, may be {@code null} + * @param startIndexInclusive + * the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in no + * change. + * @param endIndexExclusive + * elements up to endIndex-1 are shifted in the array. Undervalue (< start index) results in no + * change. Overvalue (>array.length) is demoted to array length. + * @param offset + * The number of positions to rotate the elements. If the offset is larger than the number of elements to + * rotate, than the effective offset is modulo the number of elements to rotate. + * @since 3.5 + */ + public static void shift(final short[] array, int startIndexInclusive, int endIndexExclusive, int offset) { + if (array == null || startIndexInclusive >= array.length - 1 || endIndexExclusive <= 0) { + return; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive >= array.length) { + endIndexExclusive = array.length; + } + int n = endIndexExclusive - startIndexInclusive; + if (n <= 1) { + return; + } + offset %= n; + if (offset < 0) { + offset += n; + } + // For algorithm explanations and proof of O(n) time complexity and O(1) space complexity + // see https://beradrian.wordpress.com/2015/04/07/shift-an-array-in-on-in-place/ + while (n > 1 && offset > 0) { + final int n_offset = n - offset; + + if (offset > n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n - n_offset, n_offset); + n = offset; + offset -= n_offset; + } else if (offset < n_offset) { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + startIndexInclusive += offset; + n = n_offset; + } else { + swap(array, startIndexInclusive, startIndexInclusive + n_offset, offset); + break; + } + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final boolean[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final boolean[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final byte[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final byte[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final char[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final char[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final double[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final double[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final float[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final float[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final int[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final int[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final long[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final long[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final Object[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final Object[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final short[] array) { + shuffle(array, random()); + } + + /** + * Randomly permutes the elements of the specified array using the Fisher-Yates algorithm. + * + * @param array the array to shuffle + * @param random the source of randomness used to permute the elements + * @see <a href="https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle">Fisher-Yates shuffle algorithm</a> + * @since 3.6 + */ + public static void shuffle(final short[] array, final Random random) { + for (int i = array.length; i > 1; i--) { + swap(array, i - 1, random.nextInt(i), 1); + } + } + + /** + * Produces a new {@code boolean} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(boolean[], int, int) + */ + public static boolean[] subarray(final boolean[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_BOOLEAN_ARRAY; + } + + final boolean[] subarray = new boolean[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new {@code byte} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(byte[], int, int) + */ + public static byte[] subarray(final byte[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_BYTE_ARRAY; + } + + final byte[] subarray = new byte[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new {@code char} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(char[], int, int) + */ + public static char[] subarray(final char[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_CHAR_ARRAY; + } + + final char[] subarray = new char[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new {@code double} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(double[], int, int) + */ + public static double[] subarray(final double[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_DOUBLE_ARRAY; + } + + final double[] subarray = new double[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new {@code float} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(float[], int, int) + */ + public static float[] subarray(final float[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_FLOAT_ARRAY; + } + + final float[] subarray = new float[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new {@code int} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(int[], int, int) + */ + public static int[] subarray(final int[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_INT_ARRAY; + } + + final int[] subarray = new int[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new {@code long} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(long[], int, int) + */ + public static long[] subarray(final long[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_LONG_ARRAY; + } + + final long[] subarray = new long[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new {@code short} array containing the elements + * between the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(short[], int, int) + */ + public static short[] subarray(final short[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + if (newSize <= 0) { + return EMPTY_SHORT_ARRAY; + } + + final short[] subarray = new short[newSize]; + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Produces a new array containing the elements between + * the start and end indices. + * <p> + * The start index is inclusive, the end index exclusive. + * Null array input produces null output. + * </p> + * <p> + * The component type of the subarray is always the same as + * that of the input array. Thus, if the input is an array of type + * {@link Date}, the following usage is envisaged: + * </p> + * <pre> + * Date[] someDates = (Date[]) ArrayUtils.subarray(allDates, 2, 5); + * </pre> + * + * @param <T> the component type of the array + * @param array the array + * @param startIndexInclusive the starting index. Undervalue (<0) + * is promoted to 0, overvalue (>array.length) results + * in an empty array. + * @param endIndexExclusive elements up to endIndex-1 are present in the + * returned subarray. Undervalue (< startIndex) produces + * empty array, overvalue (>array.length) is demoted to + * array length. + * @return a new array containing the elements between + * the start and end indices. + * @since 2.1 + * @see Arrays#copyOfRange(Object[], int, int) + */ + public static <T> T[] subarray(final T[] array, int startIndexInclusive, int endIndexExclusive) { + if (array == null) { + return null; + } + if (startIndexInclusive < 0) { + startIndexInclusive = 0; + } + if (endIndexExclusive > array.length) { + endIndexExclusive = array.length; + } + final int newSize = endIndexExclusive - startIndexInclusive; + final Class<T> type = getComponentType(array); + if (newSize <= 0) { + return newInstance(type, 0); + } + final T[] subarray = newInstance(type, newSize); + System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); + return subarray; + } + + /** + * Swaps two elements in the given boolean array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3], 0, 2) -> [3, 2, 1]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 0) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 1, 0) -> [2, 1, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 5) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], -1, 1) -> [2, 1, 3]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final boolean[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + + /** + * Swaps a series of elements in the given boolean array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([true, false, true, false], 0, 2, 1) -> [true, false, true, false]</li> + * <li>ArrayUtils.swap([true, false, true, false], 0, 0, 1) -> [true, false, true, false]</li> + * <li>ArrayUtils.swap([true, false, true, false], 0, 2, 2) -> [true, false, true, false]</li> + * <li>ArrayUtils.swap([true, false, true, false], -3, 2, 2) -> [true, false, true, false]</li> + * <li>ArrayUtils.swap([true, false, true, false], 0, 3, 3) -> [false, false, true, true]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final boolean[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final boolean aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Swaps two elements in the given byte array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3], 0, 2) -> [3, 2, 1]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 0) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 1, 0) -> [2, 1, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 5) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], -1, 1) -> [2, 1, 3]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final byte[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given byte array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -> [3, 2, 1, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -> [1, 2, 3, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -> [4, 2, 3, 1]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final byte[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final byte aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Swaps two elements in the given char array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3], 0, 2) -> [3, 2, 1]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 0) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 1, 0) -> [2, 1, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 5) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], -1, 1) -> [2, 1, 3]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final char[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given char array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -> [3, 2, 1, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -> [1, 2, 3, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -> [4, 2, 3, 1]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final char[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final char aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Swaps two elements in the given double array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3], 0, 2) -> [3, 2, 1]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 0) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 1, 0) -> [2, 1, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 5) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], -1, 1) -> [2, 1, 3]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final double[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given double array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -> [3, 2, 1, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -> [1, 2, 3, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -> [4, 2, 3, 1]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final double[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final double aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Swaps two elements in the given float array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3], 0, 2) -> [3, 2, 1]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 0) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 1, 0) -> [2, 1, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 5) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], -1, 1) -> [2, 1, 3]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final float[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given float array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -> [3, 2, 1, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -> [1, 2, 3, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -> [4, 2, 3, 1]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final float[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final float aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + + } + + /** + * Swaps two elements in the given int array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3], 0, 2) -> [3, 2, 1]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 0) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 1, 0) -> [2, 1, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 5) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], -1, 1) -> [2, 1, 3]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final int[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given int array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -> [3, 2, 1, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -> [1, 2, 3, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -> [4, 2, 3, 1]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final int[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final int aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Swaps two elements in the given long array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([true, false, true], 0, 2) -> [true, false, true]</li> + * <li>ArrayUtils.swap([true, false, true], 0, 0) -> [true, false, true]</li> + * <li>ArrayUtils.swap([true, false, true], 1, 0) -> [false, true, true]</li> + * <li>ArrayUtils.swap([true, false, true], 0, 5) -> [true, false, true]</li> + * <li>ArrayUtils.swap([true, false, true], -1, 1) -> [false, true, true]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final long[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given long array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -> [3, 2, 1, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -> [1, 2, 3, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -> [4, 2, 3, 1]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final long[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final long aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Swaps two elements in the given array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap(["1", "2", "3"], 0, 2) -> ["3", "2", "1"]</li> + * <li>ArrayUtils.swap(["1", "2", "3"], 0, 0) -> ["1", "2", "3"]</li> + * <li>ArrayUtils.swap(["1", "2", "3"], 1, 0) -> ["2", "1", "3"]</li> + * <li>ArrayUtils.swap(["1", "2", "3"], 0, 5) -> ["1", "2", "3"]</li> + * <li>ArrayUtils.swap(["1", "2", "3"], -1, 1) -> ["2", "1", "3"]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final Object[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap(["1", "2", "3", "4"], 0, 2, 1) -> ["3", "2", "1", "4"]</li> + * <li>ArrayUtils.swap(["1", "2", "3", "4"], 0, 0, 1) -> ["1", "2", "3", "4"]</li> + * <li>ArrayUtils.swap(["1", "2", "3", "4"], 2, 0, 2) -> ["3", "4", "1", "2"]</li> + * <li>ArrayUtils.swap(["1", "2", "3", "4"], -3, 2, 2) -> ["3", "4", "1", "2"]</li> + * <li>ArrayUtils.swap(["1", "2", "3", "4"], 0, 3, 3) -> ["4", "2", "3", "1"]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final Object[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final Object aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Swaps two elements in the given short array. + * + * <p>There is no special handling for multi-dimensional arrays. This method + * does nothing for a {@code null} or empty input array or for overflow indices. + * Negative indices are promoted to 0(zero).</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3], 0, 2) -> [3, 2, 1]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 0) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 1, 0) -> [2, 1, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], 0, 5) -> [1, 2, 3]</li> + * <li>ArrayUtils.swap([1, 2, 3], -1, 1) -> [2, 1, 3]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element to swap + * @param offset2 the index of the second element to swap + * @since 3.5 + */ + public static void swap(final short[] array, final int offset1, final int offset2) { + swap(array, offset1, offset2, 1); + } + + /** + * Swaps a series of elements in the given short array. + * + * <p>This method does nothing for a {@code null} or empty input array or + * for overflow indices. Negative indices are promoted to 0(zero). If any + * of the sub-arrays to swap falls outside of the given array, then the + * swap is stopped at the end of the array and as many as possible elements + * are swapped.</p> + * + * Examples: + * <ul> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 2, 1) -> [3, 2, 1, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 0, 1) -> [1, 2, 3, 4]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 2, 0, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], -3, 2, 2) -> [3, 4, 1, 2]</li> + * <li>ArrayUtils.swap([1, 2, 3, 4], 0, 3, 3) -> [4, 2, 3, 1]</li> + * </ul> + * + * @param array the array to swap, may be {@code null} + * @param offset1 the index of the first element in the series to swap + * @param offset2 the index of the second element in the series to swap + * @param len the number of elements to swap starting with the given indices + * @since 3.5 + */ + public static void swap(final short[] array, int offset1, int offset2, int len) { + if (isEmpty(array) || offset1 >= array.length || offset2 >= array.length) { + return; + } + if (offset1 < 0) { + offset1 = 0; + } + if (offset2 < 0) { + offset2 = 0; + } + if (offset1 == offset2) { + return; + } + len = Math.min(Math.min(len, array.length - offset1), array.length - offset2); + for (int i = 0; i < len; i++, offset1++, offset2++) { + final short aux = array[offset1]; + array[offset1] = array[offset2]; + array[offset2] = aux; + } + } + + /** + * Create a type-safe generic array. + * <p> + * The Java language does not allow an array to be created from a generic type: + * </p> + * <pre> + public static <T> T[] createAnArray(int size) { + return new T[size]; // compiler error here + } + public static <T> T[] createAnArray(int size) { + return (T[]) new Object[size]; // ClassCastException at runtime + } + * </pre> + * <p> + * Therefore new arrays of generic types can be created with this method. + * For example, an array of Strings can be created: + * </p> + * <pre> + String[] array = ArrayUtils.toArray("1", "2"); + String[] emptyArray = ArrayUtils.<String>toArray(); + * </pre> + * <p> + * The method is typically used in scenarios, where the caller itself uses generic types + * that have to be combined into an array. + * </p> + * <p> + * Note, this method makes only sense to provide arguments of the same type so that the + * compiler can deduce the type of the array itself. While it is possible to select the + * type explicitly like in + * {@code Number[] array = ArrayUtils.<Number>toArray(Integer.valueOf(42), Double.valueOf(Math.PI))}, + * there is no real advantage when compared to + * {@code new Number[] {Integer.valueOf(42), Double.valueOf(Math.PI)}}. + * </p> + * + * @param <T> the array's element type + * @param items the varargs array items, null allowed + * @return the array, not null unless a null array is passed in + * @since 3.0 + */ + public static <T> T[] toArray(@SuppressWarnings("unchecked") final T... items) { + return items; + } + + /** + * Converts the given array into a {@link java.util.Map}. Each element of the array + * must be either a {@link java.util.Map.Entry} or an Array, containing at least two + * elements, where the first element is used as key and the second as + * value. + * <p> + * This method can be used to initialize: + * </p> + * <pre> + * // Create a Map mapping colors. + * Map colorMap = ArrayUtils.toMap(new String[][] { + * {"RED", "#FF0000"}, + * {"GREEN", "#00FF00"}, + * {"BLUE", "#0000FF"}}); + * </pre> + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array an array whose elements are either a {@link java.util.Map.Entry} or + * an Array containing at least two elements, may be {@code null} + * @return a {@link Map} that was created from the array + * @throws IllegalArgumentException if one element of this Array is + * itself an Array containing less than two elements + * @throws IllegalArgumentException if the array contains elements other + * than {@link java.util.Map.Entry} and an Array + */ + public static Map<Object, Object> toMap(final Object[] array) { + if (array == null) { + return null; + } + final Map<Object, Object> map = new HashMap<>((int) (array.length * 1.5)); + for (int i = 0; i < array.length; i++) { + final Object object = array[i]; + if (object instanceof Map.Entry<?, ?>) { + final Map.Entry<?, ?> entry = (Map.Entry<?, ?>) object; + map.put(entry.getKey(), entry.getValue()); + } else if (object instanceof Object[]) { + final Object[] entry = (Object[]) object; + if (entry.length < 2) { + throw new IllegalArgumentException("Array element " + i + ", '" + + object + + "', has a length less than 2"); + } + map.put(entry[0], entry[1]); + } else { + throw new IllegalArgumentException("Array element " + i + ", '" + + object + + "', is neither of type Map.Entry nor an Array"); + } + } + return map; + } + + /** + * Converts an array of primitive booleans to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array a {@code boolean} array + * @return a {@link Boolean} array, {@code null} if null array input + */ + public static Boolean[] toObject(final boolean[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_BOOLEAN_OBJECT_ARRAY; + } + final Boolean[] result = new Boolean[array.length]; + return setAll(result, i -> array[i] ? Boolean.TRUE : Boolean.FALSE); + } + + /** + * Converts an array of primitive bytes to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array a {@code byte} array + * @return a {@link Byte} array, {@code null} if null array input + */ + public static Byte[] toObject(final byte[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_BYTE_OBJECT_ARRAY; + } + return setAll(new Byte[array.length], i -> Byte.valueOf(array[i])); + } + + /** + * Converts an array of primitive chars to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array a {@code char} array + * @return a {@link Character} array, {@code null} if null array input + */ + public static Character[] toObject(final char[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_CHARACTER_OBJECT_ARRAY; + } + return setAll(new Character[array.length], i -> Character.valueOf(array[i])); + } + + /** + * Converts an array of primitive doubles to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array a {@code double} array + * @return a {@link Double} array, {@code null} if null array input + */ + public static Double[] toObject(final double[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_DOUBLE_OBJECT_ARRAY; + } + return setAll(new Double[array.length], i -> Double.valueOf(array[i])); + } + + /** + * Converts an array of primitive floats to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array a {@code float} array + * @return a {@link Float} array, {@code null} if null array input + */ + public static Float[] toObject(final float[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_FLOAT_OBJECT_ARRAY; + } + return setAll(new Float[array.length], i -> Float.valueOf(array[i])); + } + + /** + * Converts an array of primitive ints to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array an {@code int} array + * @return an {@link Integer} array, {@code null} if null array input + */ + public static Integer[] toObject(final int[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_INTEGER_OBJECT_ARRAY; + } + return setAll(new Integer[array.length], i -> Integer.valueOf(array[i])); + } + + /** + * Converts an array of primitive longs to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array a {@code long} array + * @return a {@link Long} array, {@code null} if null array input + */ + public static Long[] toObject(final long[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_LONG_OBJECT_ARRAY; + } + return setAll(new Long[array.length], i -> Long.valueOf(array[i])); + } + + /** + * Converts an array of primitive shorts to objects. + * + * <p>This method returns {@code null} for a {@code null} input array.</p> + * + * @param array a {@code short} array + * @return a {@link Short} array, {@code null} if null array input + */ + public static Short[] toObject(final short[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_SHORT_OBJECT_ARRAY; + } + return setAll(new Short[array.length], i -> Short.valueOf(array[i])); + } + + /** + * Converts an array of object Booleans to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * <p> + * Null array elements map to false, like {@code Boolean.parseBoolean(null)} and its callers return false. + * </p> + * + * @param array a {@link Boolean} array, may be {@code null} + * @return a {@code boolean} array, {@code null} if null array input + */ + public static boolean[] toPrimitive(final Boolean[] array) { + return toPrimitive(array, false); + } + + /** + * Converts an array of object Booleans to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Boolean} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return a {@code boolean} array, {@code null} if null array input + */ + public static boolean[] toPrimitive(final Boolean[] array, final boolean valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_BOOLEAN_ARRAY; + } + final boolean[] result = new boolean[array.length]; + for (int i = 0; i < array.length; i++) { + final Boolean b = array[i]; + result[i] = b == null ? valueForNull : b.booleanValue(); + } + return result; + } + + /** + * Converts an array of object Bytes to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Byte} array, may be {@code null} + * @return a {@code byte} array, {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + */ + public static byte[] toPrimitive(final Byte[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_BYTE_ARRAY; + } + final byte[] result = new byte[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].byteValue(); + } + return result; + } + + /** + * Converts an array of object Bytes to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Byte} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return a {@code byte} array, {@code null} if null array input + */ + public static byte[] toPrimitive(final Byte[] array, final byte valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_BYTE_ARRAY; + } + final byte[] result = new byte[array.length]; + for (int i = 0; i < array.length; i++) { + final Byte b = array[i]; + result[i] = b == null ? valueForNull : b.byteValue(); + } + return result; + } + + /** + * Converts an array of object Characters to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Character} array, may be {@code null} + * @return a {@code char} array, {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + */ + public static char[] toPrimitive(final Character[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_CHAR_ARRAY; + } + final char[] result = new char[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].charValue(); + } + return result; + } + + /** + * Converts an array of object Character to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Character} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return a {@code char} array, {@code null} if null array input + */ + public static char[] toPrimitive(final Character[] array, final char valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_CHAR_ARRAY; + } + final char[] result = new char[array.length]; + for (int i = 0; i < array.length; i++) { + final Character b = array[i]; + result[i] = b == null ? valueForNull : b.charValue(); + } + return result; + } + + /** + * Converts an array of object Doubles to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Double} array, may be {@code null} + * @return a {@code double} array, {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + */ + public static double[] toPrimitive(final Double[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_DOUBLE_ARRAY; + } + final double[] result = new double[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].doubleValue(); + } + return result; + } + + /** + * Converts an array of object Doubles to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Double} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return a {@code double} array, {@code null} if null array input + */ + public static double[] toPrimitive(final Double[] array, final double valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_DOUBLE_ARRAY; + } + final double[] result = new double[array.length]; + for (int i = 0; i < array.length; i++) { + final Double b = array[i]; + result[i] = b == null ? valueForNull : b.doubleValue(); + } + return result; + } + + /** + * Converts an array of object Floats to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Float} array, may be {@code null} + * @return a {@code float} array, {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + */ + public static float[] toPrimitive(final Float[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_FLOAT_ARRAY; + } + final float[] result = new float[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].floatValue(); + } + return result; + } + + /** + * Converts an array of object Floats to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Float} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return a {@code float} array, {@code null} if null array input + */ + public static float[] toPrimitive(final Float[] array, final float valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_FLOAT_ARRAY; + } + final float[] result = new float[array.length]; + for (int i = 0; i < array.length; i++) { + final Float b = array[i]; + result[i] = b == null ? valueForNull : b.floatValue(); + } + return result; + } + + /** + * Converts an array of object Integers to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Integer} array, may be {@code null} + * @return an {@code int} array, {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + */ + public static int[] toPrimitive(final Integer[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_INT_ARRAY; + } + final int[] result = new int[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].intValue(); + } + return result; + } + + /** + * Converts an array of object Integer to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Integer} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return an {@code int} array, {@code null} if null array input + */ + public static int[] toPrimitive(final Integer[] array, final int valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_INT_ARRAY; + } + final int[] result = new int[array.length]; + for (int i = 0; i < array.length; i++) { + final Integer b = array[i]; + result[i] = b == null ? valueForNull : b.intValue(); + } + return result; + } + + /** + * Converts an array of object Longs to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Long} array, may be {@code null} + * @return a {@code long} array, {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + */ + public static long[] toPrimitive(final Long[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_LONG_ARRAY; + } + final long[] result = new long[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].longValue(); + } + return result; + } + + /** + * Converts an array of object Long to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Long} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return a {@code long} array, {@code null} if null array input + */ + public static long[] toPrimitive(final Long[] array, final long valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_LONG_ARRAY; + } + final long[] result = new long[array.length]; + for (int i = 0; i < array.length; i++) { + final Long b = array[i]; + result[i] = b == null ? valueForNull : b.longValue(); + } + return result; + } + + /** + * Create an array of primitive type from an array of wrapper types. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array an array of wrapper object + * @return an array of the corresponding primitive type, or the original array + * @since 3.5 + */ + public static Object toPrimitive(final Object array) { + if (array == null) { + return null; + } + final Class<?> ct = array.getClass().getComponentType(); + final Class<?> pt = ClassUtils.wrapperToPrimitive(ct); + if (Boolean.TYPE.equals(pt)) { + return toPrimitive((Boolean[]) array); + } + if (Character.TYPE.equals(pt)) { + return toPrimitive((Character[]) array); + } + if (Byte.TYPE.equals(pt)) { + return toPrimitive((Byte[]) array); + } + if (Integer.TYPE.equals(pt)) { + return toPrimitive((Integer[]) array); + } + if (Long.TYPE.equals(pt)) { + return toPrimitive((Long[]) array); + } + if (Short.TYPE.equals(pt)) { + return toPrimitive((Short[]) array); + } + if (Double.TYPE.equals(pt)) { + return toPrimitive((Double[]) array); + } + if (Float.TYPE.equals(pt)) { + return toPrimitive((Float[]) array); + } + return array; + } + + /** + * Converts an array of object Shorts to primitives. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Short} array, may be {@code null} + * @return a {@code byte} array, {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + */ + public static short[] toPrimitive(final Short[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_SHORT_ARRAY; + } + final short[] result = new short[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].shortValue(); + } + return result; + } + + /** + * Converts an array of object Short to primitives handling {@code null}. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array a {@link Short} array, may be {@code null} + * @param valueForNull the value to insert if {@code null} found + * @return a {@code byte} array, {@code null} if null array input + */ + public static short[] toPrimitive(final Short[] array, final short valueForNull) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_SHORT_ARRAY; + } + final short[] result = new short[array.length]; + for (int i = 0; i < array.length; i++) { + final Short b = array[i]; + result[i] = b == null ? valueForNull : b.shortValue(); + } + return result; + } + + /** + * Outputs an array as a String, treating {@code null} as an empty array. + * <p> + * Multi-dimensional arrays are handled correctly, including + * multi-dimensional primitive arrays. + * </p> + * <p> + * The format is that of Java source code, for example {@code {a,b}}. + * </p> + * + * @param array the array to get a toString for, may be {@code null} + * @return a String representation of the array, '{}' if null array input + */ + public static String toString(final Object array) { + return toString(array, "{}"); + } + + /** + * Outputs an array as a String handling {@code null}s. + * <p> + * Multi-dimensional arrays are handled correctly, including + * multi-dimensional primitive arrays. + * </p> + * <p> + * The format is that of Java source code, for example {@code {a,b}}. + * </p> + * + * @param array the array to get a toString for, may be {@code null} + * @param stringIfNull the String to return if the array is {@code null} + * @return a String representation of the array + */ + public static String toString(final Object array, final String stringIfNull) { + if (array == null) { + return stringIfNull; + } + return new ToStringBuilder(array, ToStringStyle.SIMPLE_STYLE).append(array).toString(); + } + + /** + * Returns an array containing the string representation of each element in the argument array. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the {@code Object[]} to be processed, may be null + * @return {@code String[]} of the same size as the source with its element's string representation, + * {@code null} if null array input + * @throws NullPointerException if an array element is {@code null} + * @since 3.6 + */ + public static String[] toStringArray(final Object[] array) { + if (array == null) { + return null; + } + if (array.length == 0) { + return EMPTY_STRING_ARRAY; + } + + final String[] result = new String[array.length]; + for (int i = 0; i < array.length; i++) { + result[i] = array[i].toString(); + } + + return result; + } + + /** + * Returns an array containing the string representation of each element in the argument + * array handling {@code null} elements. + * <p> + * This method returns {@code null} for a {@code null} input array. + * </p> + * + * @param array the Object[] to be processed, may be null + * @param valueForNullElements the value to insert if {@code null} is found + * @return a {@link String} array, {@code null} if null array input + * @since 3.6 + */ + public static String[] toStringArray(final Object[] array, final String valueForNullElements) { + if (null == array) { + return null; + } + if (array.length == 0) { + return EMPTY_STRING_ARRAY; + } + + final String[] result = new String[array.length]; + for (int i = 0; i < array.length; i++) { + final Object object = array[i]; + result[i] = object == null ? valueForNullElements : object.toString(); + } + + return result; + } + + /** + * ArrayUtils instances should NOT be constructed in standard programming. + * Instead, the class should be used as {@code ArrayUtils.clone(new int[] {2})}. + * <p> + * This constructor is public to permit tools that require a JavaBean instance + * to operate. + * </p> + */ + public ArrayUtils() { + } +} |