#简单工厂

#构造器

写变量对象时，字面量需要一个个定义，每次都要写很麻烦

const liLei = {
  name: '李雷',
  age: 25,
  career: 'coder',
}
const wangBa = {
  name: '王八',
  age: 29,
  career: 'product manager',
}

通过构造器批量构造

function User(name, age, career) {
  this.name = name
  this.age = age
  this.career = career
}

这样就讲变与不变分离，变的是值，不变的是属性，每次只需要传入新的值即可

#简单工厂模式

那如果人的 work 会根据 career 变化，构造器就不够了，需要通过 if 逻辑来赋值

这时候需要工厂

function Coder(name, age) {
  this.name = name
  this.age = age
  this.career = 'coder'
  this.work = ['写代码', '写系分', '修Bug']
}
function ProductManager(name, age) {
  this.name = name
  this.age = age
  this.career = 'product manager'
  this.work = ['订会议室', '写PRD', '催更']
}

工厂可以封装逻辑，将处理后的值传入构造器

function User(name , age, career, work) {
    this.name = name
    this.age = age
    this.career = career
    this.work = work
}

function Factory(name, age, career) {
    let work
    switch(career) {
        case 'coder':
            work =  ['写代码','写系分', '修Bug']
            break
        case 'product manager':
            work = ['订会议室', '写PRD', '催更']
            break
        case 'boss':
            work = ['喝茶', '看报', '见客户']
        case 'xxx':
            // 其它工种的职责分配
            ...

    return new User(name, age, career, work)
}

工厂封装了构造的逻辑

#小结

构造器是将创建对象的过程单独封装，解决的是创建多个对象实例的问题简单工厂是将创建类的过程单独封装，解决的是创建多个类的问题