If/else is killing me, something smarter?

Hi there

Im kinda new to both WordPress and PHP, so this is kinda uphill right now. I managed to do a if-elseif-else that works perfectly, but now im stuck with some more advanced stuff.

I have a field called ArticleLink. This contains a url either starting with https://, https://www., both or none of them.

What I would like is a function to do at check and make the outcome a valid url starting with https://www. regardless how it starts

How do I do that?

Thanks,
Kenneth