How do observables differ from promises in angular?

Answer»

Both observables and promises DEAL with asynchronous functionalities in Javascript however differ by one another-

	Observables	Promises
1.	Observables are lazy i.e. they won't be executed until we subscribe them by subscribe() method.	Are not lazy i.e. they executed just after creation.
2.	They deal with multiple asynchronous EVENTS at a time.	Promises handle SINGLE asynchronous events at a time.
3.	You can cancel the SUBSCRIPTION using the unsubscribe() method.	They are not cancellable.
4.	Observables deliver bugs to the subscribers.	It passes the ERRORS to child promises.

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