ES6 Classes & Constructors

What behavioral design pattern is implemented by the EventEmitter class?

class EventEmitter {
  constructor() {
    this.events = {};
  }
  
  on(event, listener) {
    if (!this.events[event]) {
      this.events[event] = [];
    }
    this.events[event].push(listener);
    return this;
  }
  
  emit(event, ...args) {
    if (!this.events[event]) return false;
    this.events[event].forEach(listener => listener(...args));
    return true;
  }
}

Observer pattern
This class implements the Observer pattern: 1) It provides a way for objects to subscribe to events, 2) It maintains a list of subscribers (listeners) for each event type, 3) It notifies all subscribers when an event occurs, 4) It's similar to Node.js's EventEmitter, 5) Enables loose coupling between components that need to interact, 6) This pattern is fundamental to event-driven programming in JavaScript.
Mediator pattern
Command pattern
Strategy pattern

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