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);

.