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);