Android Array Add add(T[] array, int index, T element)

Description

Inserts the specified element at the specified position in the array.

License

Apache License

Parameter

Parameter	Description
array	the array to add the element to, may be <code>null</code>
index	the position of the new object
element	the object to add

Exception

Parameter	Description
IndexOutOfBoundsException	if the index is out of range(index < 0 || index > array.length).
IllegalArgumentException	if both array and element are null

Return

A new array containing the existing elements and the new element

Declaration

public static <T> T[] add(T[] array, int index, T element) 

Method Source Code

//package com.java2s;
/*/*ww w  . j av a 2 s. c  om*/
 * 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.
 */

import java.lang.reflect.Array;

public class Main {
    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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)      = [null]
     * 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 array  the array to "add" the element to, may be <code>null</code>
     * @param element  the object to add, may be <code>null</code>
     * @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(T[] array, T element) {
        Class<?> type;
        if (array != null) {
            type = array.getClass();
        } else if (element != null) {
            type = element.getClass();
        } else {
            throw new IllegalArgumentException(
                    "Arguments cannot both be null");
        }
        @SuppressWarnings("unchecked")
        // type must be T
        T[] newArray = (T[]) copyArrayGrow1(array, type);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(boolean[] array, boolean element) {
        boolean[] newArray = (boolean[]) copyArrayGrow1(array, Boolean.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(byte[] array, byte element) {
        byte[] newArray = (byte[]) copyArrayGrow1(array, Byte.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(char[] array, char element) {
        char[] newArray = (char[]) copyArrayGrow1(array, Character.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(double[] array, double element) {
        double[] newArray = (double[]) copyArrayGrow1(array, Double.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(float[] array, float element) {
        float[] newArray = (float[]) copyArrayGrow1(array, Float.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(int[] array, int element) {
        int[] newArray = (int[]) copyArrayGrow1(array, Integer.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(long[] array, long element) {
        long[] newArray = (long[]) copyArrayGrow1(array, Long.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>Copies the given array and adds the given element at the end of the new array.</p>
     *
     * <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</code>, 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</code>
     * @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(short[] array, short element) {
        short[] newArray = (short[]) copyArrayGrow1(array, Short.TYPE);
        newArray[newArray.length - 1] = element;
        return newArray;
    }

    /**
     * <p>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>
     *
     * <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</code>, a new one element array is returned
     *  whose component type is the same as the element.</p>
     *
     * <pre>
     * ArrayUtils.add(null, 0, null)      = [null]
     * 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 array  the array to add the element to, may be <code>null</code>
     * @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
     */
    public static <T> T[] add(T[] array, int index, T element) {
        Class<?> clss = null;
        if (array != null) {
            clss = array.getClass().getComponentType();
        } else if (element != null) {
            clss = element.getClass();
        } else {
            throw new IllegalArgumentException(
                    "Array and element cannot both be null");
        }
        @SuppressWarnings("unchecked")
        // the add method creates an array of type clss, which is type T
        final T[] newArray = (T[]) add(array, index, element, clss);
        return newArray;
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static boolean[] add(boolean[] array, int index, boolean element) {
        return (boolean[]) add(array, index, Boolean.valueOf(element),
                Boolean.TYPE);
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static char[] add(char[] array, int index, char element) {
        return (char[]) add(array, index, Character.valueOf(element),
                Character.TYPE);
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static byte[] add(byte[] array, int index, byte element) {
        return (byte[]) add(array, index, Byte.valueOf(element), Byte.TYPE);
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static short[] add(short[] array, int index, short element) {
        return (short[]) add(array, index, Short.valueOf(element),
                Short.TYPE);
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static int[] add(int[] array, int index, int element) {
        return (int[]) add(array, index, Integer.valueOf(element),
                Integer.TYPE);
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static long[] add(long[] array, int index, long element) {
        return (long[]) add(array, index, Long.valueOf(element), Long.TYPE);
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static float[] add(float[] array, int index, float element) {
        return (float[]) add(array, index, Float.valueOf(element),
                Float.TYPE);
    }

    /**
     * <p>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>
     *
     * <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</code>, 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</code>
     * @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).
     */
    public static double[] add(double[] array, int index, double element) {
        return (double[]) add(array, index, Double.valueOf(element),
                Double.TYPE);
    }

    /**
     * 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</code>
     * @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(Object array, int index, Object element,
            Class<?> clss) {
        if (array == null) {
            if (index != 0) {
                throw new IndexOutOfBoundsException("Index: " + index
                        + ", Length: 0");
            }
            Object joinedArray = Array.newInstance(clss, 1);
            Array.set(joinedArray, 0, element);
            return joinedArray;
        }
        int length = Array.getLength(array);
        if (index > length || index < 0) {
            throw new IndexOutOfBoundsException("Index: " + index
                    + ", Length: " + length);
        }
        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;
    }

    /**
     * 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</code>.
     * @param newArrayComponentType If <code>array</code> is <code>null</code>, 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(Object array,
            Class<?> newArrayComponentType) {
        if (array != null) {
            int arrayLength = Array.getLength(array);
            Object newArray = Array.newInstance(array.getClass()
                    .getComponentType(), arrayLength + 1);
            System.arraycopy(array, 0, newArray, 0, arrayLength);
            return newArray;
        }
        return Array.newInstance(newArrayComponentType, 1);
    }

    /**
     * <p>Returns the length of the specified array.
     * This method can deal with <code>Object</code> arrays and with primitive arrays.</p>
     *
     * <p>If the input array is <code>null</code>, <code>0</code> 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</code> if the array is <code>null</code>
     * @throws IllegalArgumentException if the object arguement is not an array.
     * @since 2.1
     */
    public static int getLength(Object array) {
        if (array == null) {
            return 0;
        }
        return Array.getLength(array);
    }
}

Related

1. add(Object array, int index, Object element, Class clss)
2. add(T[] array, T element)
3. add(boolean[] array, boolean element)
4. add(boolean[] array, int index, boolean element)
5. add(byte[] array, byte element)
6. add(byte[] array, int index, byte element)