10分钟掌握JavaScript设计模式

要在10分钟内掌握JavaScript设计模式是一项挑战，但可以简单了解一些常见的设计模式。

单例模式（Singleton Pattern）：确保只有一个实例被创建，并提供全局访问点。

var Singleton = (function() {var instance;function createInstance() {var object = new Object("I am the instance");return object;}return {getInstance: function() {if(!instance) {instance = createInstance();}return instance;}};})();var instance1 = Singleton.getInstance();var instance2 = Singleton.getInstance();console.log(instance1 === instance2); // 输出 true

工厂模式（Factory Pattern）：通过工厂方法创建对象，而不是使用构造函数。

function ShapeFactory() {}ShapeFactory.prototype.createShape = function(type) {if(type === "circle") {return new Circle();} else if(type === "rectangle") {return new Rectangle();} else if(type === "triangle") {return new Triangle();}};function Circle() {this.type = "circle";}function Rectangle() {this.type = "rectangle";}function Triangle() {this.type = "triangle";}var shapeFactory = new ShapeFactory();var circle = shapeFactory.createShape("circle");console.log(circle.type); // 输出 "circle"

观察者模式（Observer Pattern）：定义了一种发布-订阅模式，主题（Subject）维护一个观察者（Observer）列表，并在状态变化时通知观察者。

function Subject() {this.observers = [];}Subject.prototype.addObserver = function(observer) {this.observers.push(observer);};Subject.prototype.removeObserver = function(observer) {var index = this.observers.indexOf(observer);if(index !== -1) {this.observers.splice(index, 1);}};Subject.prototype.notifyObservers = function() {this.observers.forEach(function(observer) {observer.update();});};function Observer(name) {this.name = name;}Observer.prototype.update = function() {console.log(this.name + " received update");};var subject = new Subject();var observer1 = new Observer("Observer 1");var observer2 = new Observer("Observer 2");subject.addObserver(observer1);subject.addObserver(observer2);subject.notifyObservers(); // 输出 "Observer 1 received update" 和 "Observer 2 received update"

这些是只是一些JavaScript设计模式的简单示例。要完全掌握设计模式，需要更深入的学习和实践。