Inverse of RegEx that checks for certain characters?

Asked Feb 21 '23 at 06:26

Active Feb 21 '23 at 07:11

Viewed 26 times

I need to provide a list of regex for validating certain input, for example, the input must be within 4-8 characters:

(.){4,9}

But there's one requirement that the input cannot contain certain characters, I could figure out how I can check if the input does contain those characters:

[<=>]

But how do I make it so that it matches anything that DOESN'T contain those characters?

I thought about negating the set:

[^<=>]

But it matches as long as there's some character that's not in the set.

Thanks!

Update:

So here are a list of input and expected behaviours:

Input: OK Expected: failed to match (.){4,9}, length is less than 4

Input: 1+1=2 Expected: failed to match the regex that input cannot contain restricted characters, in this case, the equal sign =

edited Feb 21 '23 at 07:11

asked Feb 21 '23 at 06:26

Heuristic

5,087
9
54
94

Can you add an input string and the expected output ? – SaSkY Feb 21 '23 at 06:37
Why not `^[^<=>]{4,9}$`? – mousetail Feb 21 '23 at 07:19
@mousetail Yes that works, I guess the system wants to map each RegEx to a reason why it doesn't match, so if I combine two rules into one RegEx it can be difficult to show the reason why the input is not valid. – Heuristic Feb 21 '23 at 07:23
You can add both regexes – mousetail Feb 21 '23 at 07:25

Inverse of RegEx that checks for certain characters?

0 Answers0