数组去重

 1     <script>
 2         function hasContain(arr,num) {
 3             for(var i=0;i<arr.length;i++){
 4                 if(arr[i]==num){
 5                     return true;
 6                 }
 7             }
 8             return false;
 9         }
10 
11         var arr=[1,2,3,4,5,2,3,8,4];
12         var newArr=[];
13 
14         for(var i=0;i<arr.length;i++){
15             if(!hasContain(newArr,arr[i])){
16                 newArr.push(arr[i])
17             }
18         }
19         alert(newArr);  //1,2,3,4,5,8
20     </script>