JavaScript工厂模式详解

 //篮球基类 var Basketball = function() { this.intro = '篮球盛行于美国'; } Basketball.prototype = { getMember: function() { console.log('每个队伍需要五个队员'); }, getBallSize: function() { console.log('篮球很大'); } } //足球基类 var Football = function() { this.intro = '足球在世界范围内都很流行'; } Football.prototype = { getMember: function() { console.log('每个队伍需要11名队员'); }, getBallSize: function() { console.log('足球很大'); } } //运动工厂 var SportsFactory = function(name) { switch (name) { case 'NBA': return new Basketball(); case 'worldCup': return new Football(); } } //当你需要为世界杯创建一个足球的时候，只需要记住运功工厂sportsFactory即可，调用并创建 var Footnall = SportsFactory('worldCup'); console.log(Footnall); console.log(Footnall.intro); Footnall.getMember(); 

 //工厂模式 function createBook(name, time, type) { var o = new Object(); //创建一个对象，并对对象拓展属性和方法 //这是不相似的部分 o.name = name; //书本名称 o.time = time; //书本出版时间 o.type = type; //书本类型 //下面是相似的部分 o.getName = function() { console.log(this.name); }; //将对象返回 return o; } //创建两本书 var book1 = new createBook('JS book', 2021, 'js'); var book2 = new createBook('CSS book', 2019, 'css'); book1.getName(); book2.getName(); 

 var Demo = function() {} Demo.prototype = { show: function() { console.log('成功获取'); } } var d = new Demo();//正确创建实例 d.show(); //成功获取 var d = Demo();//错误创建实例 d.show(); //炸裂 

 var Demo = function() { if (!this instanceof Demo) {//判断this的指向 return new Demo(); } } Demo.prototype = { show: function() { console.log('安全模式类真好用'); } } var d = Demo(); d.show(); 

 //安全模式创建工厂类 var Factory = function(type, content) { if (this instanceof Factory) { var s = new this[type](content); return s; } else { return new Factory(type, content); } } //工厂原型中设置创建所有类型数据对象的基类 Factory.prototype = { java: function(content) { //... }, UI: function(content) { this.content = content; (function() { var div = document.createElement('div'); div.innerHTML = content; div.style.border = '1px soild red'; document.getElementById('container').appendChild(div); })(content); }, php: function(content) { //... }, javascript: function(content) { //.. } }; //创建对象 var data = [ { type: 'javascript', content: 'js哪家强' }, { type: 'java', content: 'java哪家强' }, { type: 'UI', content: 'UI哪家强' } ]; for (let index = 0; index 

 var Car = function() {} Car.prototype = { getPrice: function() { return new Error('抽象方法不能调用'); }, getSpeed: function() { return new Error('抽象方法不能调用'); } }; 

 //抽象工厂方法 var VehicleFactory = function(subType, superType) { //判断抽象工厂中是否有该抽象类 if (typeof VehicleFactory[superType] === 'function') { //缓存类 function F() {}; //继承父类属性和方法 F.prototype = new VehicleFactory[superType](); //将子类constructor指向子类 subType.constructor = subType; //子类原型继承父类 subType.prototype = new F(); } else { //不存在该抽象类则抛错 throw new Error('未创建该抽象类'); } }; //小汽车抽象类 VehicleFactory.Car = function() { this.type = 'car'; } VehicleFactory.Car.prototype = { getPrice: function() { return new Error('抽象方法不能调用'); }, getSpeed: function() { return new Error('抽象方法不能调用'); } }; //公交车抽象类 VehicleFactory.Bus = function() { this.type = 'bus'; } VehicleFactory.Bus.prototype = { getPrice: function() { return new Error('抽象方法不能调用'); }, getPassengerNum: function() { return new Error('抽象方法不能调用'); } } 

 //抽象与实现 //宝马汽车子类 var BMW = function(price, speed) { this.price = price; this.speed = speed; }; //抽象工厂实现对Car抽象类的继承 VehicleFactory(BMW, 'Car'); BMW.prototype.getPrice = function() { //重写方法 return this.price; } BMW.prototype.getSpeed = function() { return this.speed; }; //宇通公交车子类 var YUTONG = function(price, passenger) { this.price = price; this.passenger = passenger; }; //抽象工厂实现对BUS抽象类的继承 VehicleFactory(YUTONG, 'Bus'); YUTONG.prototype.getPrice = function() { return this.price; } YUTONG.prototype.getPassengerNum = function() { return this.passenger; }; //实例化类 var myBMW = new BMW('100w', '1000km/h'); console.log(myBMW.getPrice(), myBMW.getSpeed(), myBMW.type);