继承之原型继承和构造函数继承

原型继承

//无法实现多重继承,创建了一个子类的实例
//如果对子类实例的属性进行了修改，那么创建其他子类的时候都会受到影响
function superfunc(){
   this.name = "baiying";
  this.age = 18;
  this.getName = function(){
    alert(this.age +"岁的"+this.name);
   }
 }

 function sub(){
   this.hobby = 'eat';
 }


 sub.prototype = new superfunc();
 var huanglizhen = new sub();
 console.log(huanglizhen.hobby); //eat
 huanglizhen.getName();//alert "18岁的baiying"

借用构造函数:可传参

 function superfunc1(){
   this.name = "baiying";
   this.age = 18;
   this.getName = function(){
     alert(this.age +"岁的"+this.name);
   }
 }

 function sub1(){
   this.hobby = 'eat';
   superfunc1.call(this);
 }
 var huanglizhen = new sub();
 console.log(huanglizhen.hobby); //eat
 huanglizhen.getName();//alert "18岁的baiying"