RxJS Subscriber unsubscribe vs. complete

Question

I was reading through the RxJS docs and want to make sure I\'m understanding the difference between Subscriber.unsubscribe() and Subscriber.complete()

Answer 1

Subscribers don't call complete(). You can call complete() on a Subject or more typically it's called for you "indirectly" using operators such as take(), takeWhile(), ...

For example:

const s = new Subject();
const subscriber1 = s.subscribe(...);
const subscriber2 = s.subscribe(...);
s.complete(); // both subscribers will receive the complete notification

// or with `take(1)` operator it'll call `complete()` for you
const subscriber1 = s.take(1).subscribe(...);
const subscriber2 = s.take(1).subscribe(...);
s.next(42); // both subscribers will receive the complete notification

Note that calling complete() on a Subject changes its inner state and there's no way to make it non-complete again while just unsubscribing a subscriber has no effect on the Subject.

A little similar question: Observable Finally on Subscribe