I had the same problem too, i figured out that u can run your code by hitting "Control+s" wich i actually think saves the code (whats necessary cause Codewars cache's your script anyways..) but also runs your script.

What is the diffeence between / and //?

I'm also trying to switch the indentation to four spaces and don't see a way. 2-space indentation is difficult to read in JavaScript or other languages with leading characters like {, <, and ., because the blocks are not well-defined visually.

For some reason in a kata, "Control + Enter" does not run the code. All it does is make a new line in the code.

I am using firefox.

Anyone know why this is happening?