Intermediate
Web & Software Development
Q55 / 100
What is the observer pattern?
Correct! Well done.
Incorrect.
The correct answer is B) A behavioral pattern where objects (observers) subscribe to notifications from a subject, which notifies all registered observers when its state changes
B
Correct Answer
A behavioral pattern where objects (observers) subscribe to notifications from a subject, which notifies all registered observers when its state changes
Explanation
Observer pattern (publish-subscribe): EventEmitter in Node.js, addEventListener in DOM, @Output in Angular. The subject doesn't know who its observers are — loose coupling. Foundation for reactive programming.
Progress
55/100