json数组去重

 if(localStorage.getItem("selectcarmsg")){
       var arr=JSON.parse(localStorage.getItem("selectcarmsg"));
       arr.push(selectcarmsg);
        var jsonstr = [];//json去重
        outer:
       for(var i=0;i<arr.length;i++){
         inter:
         for(var j=i+1;j<arr.length;j++){
           if(arr[i].carid==arr[j].carid && arr[i].carposition==arr[j].carposition){
              // console.log(arr[i].carid+'&nbsp;&nbsp;'+arr[j].carid);
              arr.splice(i,1);
              break inter;
           }
         }
       }
       localStorage.setItem("selectcarmsg",JSON.stringify(arr));