Learn Observer, Strategy, and Command patterns. Behavioral patterns focus on communication between objects and responsibility distribution.

• Observer
• Strategy
• Command patterns

class EventEmitter {
  constructor() { this.listeners = {}; }
  on(event, callback) {
    if (!this.listeners[event]) this.listeners[event] = [];
    this.listeners[event].push(callback);
  }
// ...

• Observer pattern works
• Strategy pattern works

• Observer: subject notifies multiple observers of changes
• Strategy: define family of algorithms, encapsulate each
• Command: encapsulate request as object, defer/queue execution

Learn Observer, Strategy, and Command patterns. Behavioral patterns focus on communication between objects and responsibility distribution.

• Observer
• Strategy
• Command patterns

class EventEmitter {
  constructor() { this.listeners = {}; }
  on(event, callback) {
    if (!this.listeners[event]) this.listeners[event] = [];
    this.listeners[event].push(callback);
  }
// ...

• Observer pattern works
• Strategy pattern works

• Observer: subject notifies multiple observers of changes
• Strategy: define family of algorithms, encapsulate each
• Command: encapsulate request as object, defer/queue execution