Why does code challenge not has code playground?

Question

I think it is easier to understand the answer if there are code playground for us to play around.(after exposing the answer)

Answer 1

Seems a good idea. You can mail your suggestions at: [e-mail] or via the in-app feedback.

Answer 2

But if you use the Code playground during challenges, it may not be examined your knowledge! Because if you write the program on Code playground, you will easily get the output by compiling without any calculation or knowledge of yourself!

Answer 3

What I mean is after they already told us the answers like I have one of the question that I did not answer correctly, I come again to look for the answer but still do not understand why the answer output like this. Having code playground in there will help us understand the answers better