ES5 prototype实现继承

function Human (name) {
  this.name = name
}
Human.prototype.run = function () {}

function Man (name) {
  Human.call(this,name)  //改变自身属性
  this.gender = '男' 
}
Man.__proto__ = Human.prototype  //实现继承

var f = function () {} //IE不支持上面的写法，需要引入一个空函数
f.prototype = Human.prototype
Man.prototype = new f()

ES6 写法

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('糊你一脸')
  }
}