What is mean by slim Ul in options of code playground?

Question

Hey, if open the options of code playground you will notice a option of slim Ul . Please tell me what does it mean

Answer 1

As the name states - it fits more of the code onto the screen, and keeps the UI smaller, for coding pleasure.

Answer 2

Why don't you just try it and see the difference? or you can't see any difference from iPhoneX ?