浅析JS抽象工厂模式

const Car = function() { }Car.prototype.getPrice = function() {return new Error('抽象方法不能调用')}

/*** 实现subType类对工厂类中的superType类型的抽象类的继承* @param subType 要继承的类* @param superType 工厂类中的抽象类type*/const VehicleFactory = function(subType, superType) { if (typeof VehicleFactory[superType] === 'function') {  function F() {   this.type = '车辆'  }   F.prototype = new VehicleFactory[superType]()  subType.constructor = subType  subType.prototype = new F()        // 因为子类subType不仅需要继承superType对应的类的原型方法，还要继承其对象属性 } else throw new Error('不存在该抽象类')}VehicleFactory.Car = function() { this.type = 'car'}VehicleFactory.Car.prototype = { getPrice: function() {  return new Error('抽象方法不可使用') }, getSpeed: function() {  return new Error('抽象方法不可使用') }}const BMW = function(price, speed) { this.price = price this.speed = speed}VehicleFactory(BMW, 'Car')    // 继承Car抽象类BMW.prototype.getPrice = function() {    // 覆写getPrice方法 console.log(`BWM price is ${this.price}`)}BMW.prototype.getSpeed = function() { console.log(`BWM speed is ${this.speed}`)}const baomai5 = new BMW(30, 99)baomai5.getPrice()             // BWM price is 30baomai5 instanceof VehicleFactory.Car    // true