timer and interval in marble time in RxJS

RxJS interview exercise on Creating observables, difficulty 2 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.

Write ticks(period, count): emits 0, 1, 2 … count − 1, the first immediately and the rest every period milliseconds, then completes with the last value. ticks(anything, 0) completes at once.

Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.

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