An empty string will always return false, but in this case we should return true if the string ends up with no characters.

thanks for the advice g964, in fact I did before I asked to you.
However I don't understand why your test cases are not sorted alphabetically -> http://prntscr.com/d59r1x

Roughly: sorted alphabetically as said in the description. Some Codewarrior absolutely wanted "code point"... You could have googled it:-)

hey guys I've almost completed the kata, the sorting is okay, but I can't understand what the heck "sort by code point" means...
could anyone explain me this?
thanks

here is some documentation. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Logical_Operators#Logical_NOT