var  arr = ['*','##',"***","&&","****","##*"];
    arr[7] = "**";
    //数组长度
    var l = arr.length;
   
    //删除数组中非*的项
    var i = 0;
    for(; i < l; i++){
        var val = arr[i];

        if(val != undefined) {
            var newarr = val.split('');
            var newl = newarr.length;
            for(var j = 0; j < newl; j++){
                if(newarr[j] != '*'){
                    arr.splice(i, 1);
                    break;
                }
            }
        }
    }

下划线的位置是不是只删除了##而留下了‘*',为什么没有打印出来