javascript - 如何随机化(洗牌)JavaScript 数组？

Question

我有一个这样的数组:

var arr1 = ["a", "b", "c", "d"];

我怎样才能随机化/随机化它？

Answer 1

事实上的无偏洗牌算法是 Fisher-Yates (aka Knuth) Shuffle .

你可以看到一个great visualization here (和原帖linked to this)

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

  // While there remain elements to shuffle.
  while (currentIndex != 0) {

    // Pick a remaining element.
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex--;

    // And swap it with the current element.
    [array[currentIndex], array[randomIndex]] = [
      array[randomIndex], array[currentIndex]];
  }

  return array;
}

// Used like so
var arr = [2, 11, 37, 42];
shuffle(arr);
console.log(arr);

更多信息 about the algorithm用过。