数组打乱的代码片段

打乱给定数组，返回新数组，不修改原数组

function shuffle(arr) {
  let
    n = arr.length,
    newArr = [...arr]
  while (n) {
    let m = Math.floor(Math.random() * n-- );
    [newArr[m], newArr[n]] = [newArr[n], newArr[m]];
  }
  return newArr
}