var arr =[1,2,3,4];var t;for(var i = 0;i < arr.length; i++){ var rand = parseInt(Math.random()*arr.length);   t = arr[rand];   arr[rand] =arr[i];   arr[i] = t;}console.log(arr);

var arr =[1,2,3,4];var brr = [];var num = arr.length;for (var i = 0; i < num; i++){ var temp = parseInt(Math.random()*(num-i)); brr.push(arr[temp]); arr.splice(temp,1);}console.log(brr);

function randomsort(a, b) {  return Math.random()>.5 ? -1 : 1; //通過隨機(jī)產(chǎn)生0到1的數(shù)，然后判斷是否大于0.5從而影響排序，產(chǎn)生隨機(jī)性的效果。}var arr = [1, 2, 3, 4, 5];arr.sort(randomsort);