js继承问题

有关js继承的问题；

function Parent(){
        this.name = 'huachenyu'
      }
      function Child() {
        this.age = 12
      }

      Child.prototype = new Parent();      //Child继承Parent

      var test = new Child();
      alert(test.age)   //12

　　alert(test.name)  //huachenyu

 

　　function bro(){
        this.sex = 'boy'
      }

      bro.prototype = new Child();  //同理，bro继承Child
      var test1 = new bro();
      alert(test1.sex)  //boy