JavaScript去除数组中重复值

Array.prototype.unique = function(){  
  var a = {};
  var len = this.length;
  for(var i=0; i<len; i++)  {  
    if(typeof a[this[i]] == "undefined")  
    a[this[i]] = 1;  
  }  
  this.length = 0;  
  for(var i in a)  
  this[this.length] = i;  
  return this;  
}

 

测试

 

var arr = [1,1,1,2,2,2,3,3,4,4];
arr.unique();
alert(arr.toString()); 

 

 

结果

 

[1,2,3,4]