继承是什么

继承是什么? 继承是类和类之间的关系,使得子类具有父类的属性和方法

继承的两种写法

ES 5 写法

 function Human(name){
     this.name = name
 }
 Human.prototype.run = function(){
     console.log("我叫"+this.name+"，我在跑")
     return undefined
 }
 function Man(name){
     Human.call(this, name)
     this.gender = '男'
 }

 var f = function(){}
 f.prototype = Human.prototype
 Man.prototype = new f()

 Man.prototype.fight = function(){
     console.log('糊你熊脸')
 }

ES 6 写法（MDN 链接）

 class Human{
     constructor(name){
         this.name = name
     }
     run(){
         console.log("我叫"+this.name+"，我在跑")
         return undefined
     }
 }
 class Man extends Human{
     constructor(name){
         super(name)
         this.gender = '男'
     }
     fight(){
         console.log('糊你熊脸')
     }
 }