Overview
The observer pattern defines a relationship between more than one object where one object is observed by many others. The system is designed in such a way that when a state of the observed object is changed, all observing objects get notified automatically. This pattern is also known as dependents and pub/sub (publication/subscription).
Mainly people like to use the observer pattern in JavaScript, and there are possibilities/chances that people are using it already. We commonly use event handling on DOM elements in all size of application and that can be achieved with the use of observer pattern.
The main and very important feature of the observer pattern is that we can add or remove the observer at runtime. The observer pattern gives an ability to subscribe to an event and then give a notification to the user when the event comes into the picture. With the use of the observer pattern user can get facility of object-oriented design and it also provides loose coupling.
Many different...
