Regex (JS) — Match any 5-character combination, but ignore 5-character repeat

Question

I struggle with regular expressions, and I've been trying to make one that can match any 5-character combination of X and O , but ignore it if it repeats X or O EXACTLY 5 times.

This is what I came up with:

X{1,4}|O{1,4}
X|O{1,4}

those expressions match (I want it to ignore the XXXXX and OOOOO):

I also tried using the non-capturing group (?:) , but it didn't work out too well.

Answer 1

^(?!(.)\1+$)[XO]{5}$

Try this.See demo.

https://regex101.com/r/uK9cD8/1

Answer 2

您可以尝试以下基于断言的正则表达式。

^(?!(?:X{5}|O{5})$)(?=.*X)(?=.*O)[XO]{5}$