判断数组中不同元素出现次数

var arr1=[1,1,1,1,1,2,2,2,2,3,3,3,4,4,5,6,7,7,‘1‘,‘1‘];

     var res = [];
     var btn;

     for(var i =0;i<arr1.length;i++){
        btn = false;

        for(var j = 0;j<res.length;j++){

            if(arr1[i] === res[j].val){

                res[j].count += 1;

                btn = true;
                break;
            }

        }

        if(!btn){

            res.push({val:arr1[i],count:1});
        }

     }

     for(var i =0;i<res.length;i++){

        console.log(res[i]);
     }