JavaScript：实现支持多监听器与取消注册的发布 - 订阅模式

```javascript class Listener { constructor() {} handle(eventData) { console.log(`Received event: ${eventData}`); } } class EventEmitter { constructor() { this.listeners = {}; } on(eventName, listener) { if (!this.listeners[eventName]) { this.listeners[eventName] = []; } this.listeners[eventName].push(listener); } emit(eventName, eventData) { if (this.listeners[eventName]) { for (let listener of this.listeners[eventName]) { listener.handle(eventData); } } } off(eventName, listenerToRemove) { if (this.listeners[eventName]) { this.listeners[eventName] = this.listeners[eventName].filter( (listener) => listener!== listenerToRemove ); } } } // 测试 const emitter = new EventEmitter(); const listener1 = new Listener(); const listener2 = new Listener(); emitter.on('myEvent', listener1); emitter.on('myEvent', listener2); emitter.emit('myEvent', 'Hello, World!'); emitter.off('myEvent', listener1); emitter.emit('myEvent', 'Another message'); ``` ######[AI写代码神器 | 320点数解答 | 2024-11-09 00:55:08]