继承再问是孙子

[MJingv]

用call继承

function Parent () {
  this.name = 'parent'
}

Parent.prototype.do = function () {
  console.log(1)
}

function Child () {
  this.name = 'child'
  Parent.call(this)
}

let c = new Child()
console.log(c)

• 无法继承父亲的方法

[MJingv]

用原型链

function Parent () {
  this.name = 'parent'
}

Parent.prototype.do = function () {
  console.log(1)
}

function Child () {
  this.name = 'child'
}

Child.prototype = new Parent()
let c = new Child()
console.log(c)

• 子改父改，用的一个原型实例

[MJingv]

call+原型链

function Parent () {
  this.name = 'parent'
}

Parent.prototype.do = function () {
  console.log(1)
}

function Child () {
  Parent.call(this)
  this.name = 'child'
}

Child.prototype = new Parent() //多次调用
let c = new Child()
console.log(c)

• 多次调用

[MJingv]

寄生组合

function Parent () {
  this.name = 'parent'
}

Parent.prototype.do = function () {
  console.log(1)
}

function Child () {
  Parent.call(this)
  this.name = 'child'
}

Child.prototype = Object.create(Parent.prototype)
Child.prototype.constructor = Child
let c = new Child()
console.log(c.__proto__)

• 完美

[MJingv]

class

• 寄生组合+Object.setPrototypeOf(subClass, superClass)继承静态方法