如何实现数组的随机排序？

方法一：

var arr = [1,2,3,4,5,6,7,8,9,10];     function randSort1(arr){        for(var i = 0,len = arr.length;i < len; i++ ){            var rand = parseInt(Math.random()*len);            var temp = arr[rand];            arr[rand] = arr[i];            arr[i] = temp;        }         return arr;     }     console.log(randSort1(arr));

方法二：

var arr = [1,2,3,4,5,6,7,8,9,10];        function randSort2(arr){            var mixedArray = [];            while(arr.length > 0){                var randomIndex = parseInt(Math.random()*arr.length);                mixedArray.push(arr[randomIndex]);                arr.splice(randomIndex, 1);            }            return mixedArray;        }        console.log(randSort2(arr));

方法三：

var arr = [1,2,3,4,5,6,7,8,9,10];        arr.sort(function(){            return Math.random() - 0.5;        })        console.log(arr);