function person(name){          this.name=name;       }       person.prototype.getName=function(){          return this.name;       }      var objectFactory=function(){                     var obj=new Object(),Constructor=[].shift.call(arguments);//這個(gè)地方不是太懂           obj._proto_=Constructor.prototype;          var ret=Constructor.apply(obj,arguments);                     return typeof ret==='object'?ret:obj;       };      var a=objectFactory(person,'sven');最近在看原型繼承，看到這個(gè)demo的時(shí)候不太明白，希望大神能指點(diǎn)一下。