var arr=[1,2,3,3,4,4,5,5,6,1,9,3,25,4];         function deRepeat(){             var newArr=[];             var obj={};             var index=0;             var l=arr.length;             for(var i=0;i<l;i++){                 if(obj[arr[i]]==undefined)                   {                     obj[arr[i]]=1;                     newArr[index++]=arr[i];                   }                 else if(obj[arr[i]]==1)                   continue;             }             return newArr;          }         var newArr2=deRepeat(arr);         alert(newArr2); //输出1,2,3,4,5,6,9,25