Regex - check if a substring is not part of a pattern

Question

I would like to check in a given string that if the word TEST appears in the string then it is NOT inside the pattern ([]). The regex should return true for the following example strings:

TEST
this is my ([TEST
this is my TEST]) number 2
([bla]) TEST ([bla])

Should return false for the following example strings:

this is my ([TEST]) oops
this is my ([bla TEST bla])
this is my ([TEST TEST])
string without the tes* word

thanks

@svinja the regex should match for ([bla]) TEST ([bla]) since the pattern is closed before the TEST word. great catch. — user1116377
– user1116377, Commented May 3, 2016 at 19:16

anubhava · Accepted Answer · 2016-05-03 19:39:23Z

3

You can use this lookaheads regex:

^(?!.*\(\[(?:(?!\(\[|\]\)).)*TEST(?:(?!\(\[|\]\)).)*\]\))(?=.*TEST).*

(?!..) is negative lookahead to fail the match if ([..TEST..]) appears anywhere in the line.
(?=.*TEST) is positive lookahead to ensure that line contains TEST

RegEx Demo

edited May 3, 2016 at 19:39

answered May 3, 2016 at 19:03

anubhava

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7 Comments

Hugo S. Mendes Over a year ago

it fails for ([bla]) [TEST]([bla])

anubhava Over a year ago

That's not correct as ([bla]) [TEST]([bla]) comes as a match in the demo link.

Hugo S. Mendes Over a year ago

sorry.. that's what I meant

Hugo S. Mendes Over a year ago

it says that it's a match.. but for what I understood, it shouldn't point that as a match

user1116377 Over a year ago

@Hugo it should come as a match. anubhava thanks a lot!

|

Ankit Singh · Accepted Answer · 2016-05-03 18:56:29Z

3

/\[.*TEST.*\]/g

inverse of what you asked (see Regex101 demo), just do a '!' before match

answered May 3, 2016 at 18:56

Ankit Singh

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3 Comments

Mad Physicist Over a year ago

You might want to change your answer slightly since the flavor has been established as Java. Conceptually, your answer is fine though.

user1116377 Over a year ago

could you please explain the '!' before match?

Overv Over a year ago

@user1116377 Invert the boolean that indicates if there is a match.

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