function shuffle(array) { let counter = array.length; // While there are elements in the array while (counter > 0) { // Pick a random index let index = Math.floor(Math.random() * counter); // Decrease counter by 1 counter--; // And swap the last element with it let temp = array[counter]; array[counter] = array[index]; array[index] = temp; } return array; }
/** * 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
/** * 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; }
您可以使用Fisher-Yates Shuffle（程式碼改編自此網站）：
function shuffle(array) { let counter = array.length; // While there are elements in the array while (counter > 0) { // Pick a random index let index = Math.floor(Math.random() * counter); // Decrease counter by 1 counter--; // And swap the last element with it let temp = array[counter]; array[counter] = array[index]; array[index] = temp; } return array; }使用現代版本的 Fisher–Yates 洗牌演算法：
/** * 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
/** * 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; }但請注意，使用解構交換變數截至 2017 年 10 月，分配會導致嚴重的效能損失。
使用
實作原型
使用
Object.defineProperty（取自此SO答案的方法）我們也可以實作該函數作為陣列的原型方法，而無需讓它出現在諸如for (i in arr)之類的迴圈中。以下程式碼將允許您呼叫arr.shuffle()來隨機排列數組arr：Object.defineProperty(Array.prototype, 'shuffle', { value: function() { for (let i = this.length - 1; i > 0; i--) { const j = Math.floor(Math.random() * (i + 1)); [this[i], this[j]] = [this[j], this[i]]; } return this; } });