this method will count words that start with non-alphabetic characters (like "1st" or "_example") as neither positive nor negative.

If the string does not match regexp return null
null || [] returns [];

Nice solution!

I was just wondering – how exactly does the || [] work in this?

If the string does not match it gets put into an empty array right?
Is this array accessible or is basically like a dumping ground for letters that do not match?

you like me :))))))))))))))))))

I knew the whole time there would be a 2 liner regexp solution while typing my 20 lines of code...

I have been able to complete this kata with erroneous code. From what i have seen it seems that there is missing test case, which counts for plus sign and then the number in any notation except decimal.