闭包的完美封装

var obj = function (arg1,arg2) {
    var name = arg1;
     var age = arg2;
    function privateFunction() {
          return name;
    }
    var globalObj = {
          say:function(){
               return this.sayAge();
          },
          sayName:function(){
               alert(name);
          },
          sayAge:function(){
               alert(age);
          },
          sayP:function(){
               return privateFunction();
          }
     };
     function obj(){}
     obj.prototype = globalObj;
     return new obj(name);

}('hello world!',2);
obj.say();
alert(obj.sayP());