参考知乎的一遍文章

常用方式

原型继承

var person = { 
    friends : ["Van","Louis","Nick"];
     };
var p1 = Object.create(person); 
p1.friends.push("Rob");
var p2 = Object.create(person); 
p2.friends.push("Style"); 
console.log(person.friends); //"Van,Louis,Nick,Rob,Style"

等价于

var person = { 
    friends : ["Van","Louis","Nick"];
     };
var p1 = [];
p1.__proto__ = person
p1.friends.push("Rob");
var p2 = []
p2.__proto__ = person
p2.friends.push("Style"); 
console.log(person.friends); //"Van,Louis,Nick,Rob,Style"

就是利用了原型链的方式, 注意一下缺点

通过call apply的方法继承.

es6的extend继承