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JavaScript 乱序(洗牌)算法

· One min read

ref How to randomize (shuffle) a JavaScript array?

传统洗牌算法实现​

function shuffle(array) {
  let currentIndex = array.length;
  let temporaryValue;
  let randomIndex;

  // 当仍然有元素要洗牌时
  while (currentIndex !== 0) {
    // 选取一个剩余的元素
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // 将它与当前元素交换
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}

const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];
console.log(shuffle(arr));  // 输出乱序数组

简单实现​

array.sort(() => Math.random() - 0.5);
note

注意, 以上两种方式都会修改原数组, 有副作用.