Question

The item referenced in this question does not seem to work for me.
I’m using the Regular Expression validator in .net

I need to pass validation if the input field does NOT look like this

“bagdfsdf -CONST”

When I use “(?>!-CONST)$” and “.*(?>!-CONST)$” the regular expression validator never allows it. If I have -CONST at the end or not

Any ideas?

Answer 1

(?> … ) is the syntax for an atomic grouping. And the syntax for look-ahead assertion is just (?! … ).

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Edit   Try this regular expression instead:

.*$(?<!-CONST)

The .*$ will consume everything and the look-behind assertion will exclude those that end with a -CONST.

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Edit    Just for completeness’ sake: If your regular expression language does not allow look-behinds, you can also use this one using a look-ahead assertion:

^(.{0,5}|.*(?!-CONST).{5})$

Or using just alternations:

^(.{0,5}|.*([^-].{5}|-([^C].{4}|C([^O].{3}|O([^N].{2}|N([^S].|S[^T]))))))$