Why sololearn has no codeplayground for Swift ?

Answer 1

I think they could emulate it (it would be harder though)

Answer 2

Because it is not so useful programming language for those people who doesn't use Mac or iOS. It is not so good language for beginner programmers too. So they don't want to waste their time on it. You can use this online compiler for Swift
https://iswift.org/playground