Values, then completion in RxJS
RxJS interview exercise on Creating observables, difficulty 1 of 3. Solve it in the editor beside a worked example; the tests run the moment you do.
Write countdown(from): an observable that emits from, from − 1, … down to 1, then completes. countdown(0) completes without emitting.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.