《TypeScript 编程》5.13 练习题.3

shoeFactory.ts

type Shoe = {
  purpose: string
}

type ShoeFactory = {
  create(t: 'boot'): Boot
  create(t: 'balletFlat'): BalletFlat
  create(t: 'sneaker'): Sneaker
  create(t: string): Boot
}

class Boot implements Shoe {
  purpose = 'Boot'
}

class BalletFlat implements Shoe {
  purpose = 'BalletFlat'
}

class Sneaker implements Shoe {
  purpose = 'Sneaker'
}

let abc:ShoeFactory = {
  create(t: string):Shoe {
    switch(t) {
      case 'boot': return new Boot()
      case 'balletFlat': return new BalletFlat()
      case 'sneaker': return new Sneaker()
      default: return new Boot()
    }
  }
};

console.log(abc.create('balletFlat'));