Ok, sorry, next time i will post it as a spoiler context , I did not pay attention on that, thanks for info! I wanted to use this method, as I saw od mdn documentation I can make comparisons in argument with functions sort(). But I've just used another way to solve it. But it is good to know that I should not have abused sort methods. Thanks a lot!

Because you're abusing sort there (it's not stable in javascript btw), I think you wanted to use another method to compare the letters. Don't forget to mark your post as having spoiler content next time.