Chapter 42 — Design Patterns in JavaScript: Exercise 3 — Hard

Exercise 3 — Hard

Task:
To'liq Observer Pattern implementatsiyasini yozing: EventEmitter class'i on(eventName, callback), off(eventName, callback), emit(eventName, data) metodlariga ega bo'lsin — bu safar turli nomlangan hodisalar uchun turli obunachilarni qo'llab-quvvatlasin (bitta umumiy ro'yxat o'rniga, eventName bo'yicha guruhlangan).
Required Concepts:

• Observer Pattern
• Map yoki Object (guruhlash uchun)
  Hint:
  Ichki saqlash uchun Map yoki oddiy object ishlatib, har bir eventName uchun alohida callback array saqlang.