工厂方法模式

class Animal  {
    constructor(name)  {
        this.name=name;
    }
    eat() {
         console.log(‘吃什么呀‘)
    }
}
class  Dog  extends  Animal {
  constructor(name)  {
       super(name);
       this.call=‘汪汪‘
  }
}

class  Cat  extends  Animal {
  constructor(name)  {
       super(name);
       this.call=‘喵喵‘
  }
}

class DogFactory{
    create() {
        return new Dog(‘xiao‘);
    }
}

class CatFactory{
    create() {
        return new Cat(‘wei‘);
    }
}

 
 const settings={
    ‘dog‘: DogFactory,
    ‘cat‘: CatFactory
}
let dog=new settings[‘dog‘]().create();
console.log(dog);
let cat=new settings[‘cat‘]().create();
console.log(cat);