I like how beautiful and short your code is.

You can delete the second condition.

I thought the same as you, "What is the point of using already existing functions?". But it depends on what level you are in, if you are a beginner it is much useful and beneficial to do it from scratch, but if you have more experience you don't have to.

Actually you don't need to write that question mark and any character after it.

بارك الله فيك

That is a very clever solution.