var str = '?aa=1&bb=2&cv=3';
var res = str.substr(1);
var arr = res.split("&");
var obj = {};
for (var i = 0; i < arr.length; i++) {
// console.log(arr[i]);
var line = arr[i].split("=");
// console.log(line);
obj[line[0]] = line[1];
}
console.log(obj);
console.log(typeof obj);