Java Array Shuffle randomize(final T[] array)

Description

Reassigns all of the existing values in the given array to different (pseudo-random) slots.

License

Open Source License

Parameter

Parameter	Description
array	a parameter

Return

the randomized array.

Declaration

public static <T> T[] randomize(final T[] array) 

Method Source Code

//package com.java2s;
/*//from   ww w  .  j  ava2s.com
 *  Copyright (C) 2011-2014 Brian Groenke
 *  All rights reserved.
 * 
 *  This file is part of the 2DX Graphics Library.
 *
 *  This Source Code Form is subject to the terms of the
 *  Mozilla Public License, v. 2.0. If a copy of the MPL 
 *  was not distributed with this file, You can obtain one at 
 *  http://mozilla.org/MPL/2.0/.
 */

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Main {
    /**
     * Reassigns all of the existing values in the given array to different
     * (pseudo-random) slots.
     * 
     * @param array
     * @return the randomized array.
     */
    public static <T> T[] randomize(final T[] array) {

        if (array == null) {
            throw (new NullPointerException("passed array is of null value"));
        }
        T[] copy = Arrays.copyOf(array, array.length);
        List<Integer> track = new ArrayList<Integer>();
        for (int i = 0; i < array.length; i++) {
            int rand = -1;
            do {
                rand = (int) (Math.random() * array.length);
            } while (track.contains(rand));

            array[i] = copy[rand];
            track.add(rand);
        }
        return array;
    }
}

Related

1. shuffle()
2. shuffle(byte[] array)
3. shuffle(byte[] values, Random rnd)
4. shuffle(Collection items, Random random)