获取inpu数据进行数据重组

列如 :
var obj;
obj.spec_ids=[];

$("input[name^='spec_id']").each(function(i){
obj.spec_ids[i]=$(this).val();//获取多个同名input值
console.log(obj.spec_ids);//输出值为 ["108", "109"]

});

for(var j=0;j < obj.spec_ids.length;j++){
var spec_item_id_ =[];

     var input = "input[name^='spec_item_id_" + obj.spec_ids[j] + "']";
      spec_item_id_ = "spec_item_id_" + obj.spec_ids[j];
     $(input).each(function(i){

         obj.spec_item_id_[i]=$(this).val();//


     });

     console.log(obj.spec_item_id_);//循环输出值为["305", "306"], ["307", "308"]

}
console.log(obj);//输出结果为

obj = {

spec_item_id_: ["307", "308"],

};

想要得到下面这样一组json数据应该这样做呢?
obj = {
spec_item_id_108: ["305", "306"],
spec_item_id_109: ["307", "308"],

};

http://www.cnblogs.com/sydeveloper/p/3794079.html