Make a regex not match if a certain string is found in the match?

Question

Lets say i have some random easy match like

\bword\b

Now i want to add to this that if before this match there is lets say this

(HOUSE[ ]*?)\bword\b

So if the word HOUSE and whatever ammount of spaces is infront of word then the match should be false. So my question more or less is how do i negate the (HOUSE[ ]*?) query?

You use a negative lookbehind. In .NET lookbehinds can be infinite AFAIK so: `(? — HamZa, Jul 24 '14 at 11:15
@HamZa hm i think it will work but i was kinda trying to avoid lookarounds. Guess there is no other solution — Vajura, Jul 24 '14 at 11:27
@Vajura There should be another programmatic way. You use `(HOUSE[ ]*?)?\bword\b` and then check if group 1 exists. If it exists then the result should be false. Not sure how .NET handles the existence of group 1, but you could always check if it's empty or something like that. — HamZa, Jul 24 '14 at 11:29
@HamZa I actualy came up with excatly this 1 minute ago i think i prefer this solution — Vajura, Jul 24 '14 at 12:09

score 2 · Accepted Answer · edited May 23 '17 at 11:57

2

You use a negative lookbehind. In .NET lookbehinds can be variable length:

(?<!HOUSE[ ]*?)\bword\b

Reference:

Variable length lookbehind

edited May 23 '17 at 11:57

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answered Jul 24 '14 at 11:26

HamZa

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Make a regex not match if a certain string is found in the match?

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