what pattern is most similar to the observer design pattern?

The definition of an observer is a person watching something, or a member of an aircraft crew or the armed forces who watches and reports. An example of an observer is a student taking notes on how teachers run their classes . A crew member on a military aircraft who makes observations.

The Observer pattern offers a subscription model in which objects subscribe to an event and get notified when the event occurs . This pattern is the cornerstone of event driven programming, including JavaScript. The Observer pattern facilitates good object-oriented design and promotes loose coupling.

Observer is a behavioral design pattern that allows some objects to notify other objects about changes in their state . The Observer pattern provides a way to subscribe and unsubscribe to and from these events for any object that implements a subscriber interface. Learn more about Observer.