我如何改变阵列？ [英] How can I shuffle an array?

问题描述

可能重复：

如何随机化javascript数组？

I想要在JavaScript中随机播放一系列元素：

I want to shuffle an array of elements in JavaScript like these:

[0, 3, 3] -> [3, 0, 3]
[9, 3, 6, 0, 6] -> [0, 3, 6, 9, 6]
[3, 3, 6, 0, 6] -> [0, 3, 6, 3, 6]

推荐答案

使用 Fisher-Yates shuffle算法的现代版本：

/**
 * Shuffles array in place.
 * @param {Array} a items An array containing the items.
 */
function shuffle(a) {
    var j, x, i;
    for (i = a.length - 1; i > 0; i--) {
        j = Math.floor(Math.random() * (i + 1));
        x = a[i];
        a[i] = a[j];
        a[j] = x;
    }
    return a;
}

ES2015（ES6）版本

ES2015 (ES6) version

/**
 * Shuffles array in place. ES6 version
 * @param {Array} a items An array containing the items.
 */
function shuffle(a) {
    for (let i = a.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [a[i], a[j]] = [a[j], a[i]];
    }
    return a;
}

但请注意，交换变量解构分配导致重大性能损失，截至2017年10月。

Note however, that swapping variables with destructuring assignment causes significant performance loss, as of October 2017.

var myArray = ['1','2','3','4','5','6','7','8','9'];
shuffle(myArray);

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