How to match multiple words in regex

Question

Just a simple regex I don't know how to write.

The regex has to make sure a string matches all 3 words. I see how to make it match any of the 3:

/advancedbrain|com_ixxocart|p\=completed/

but I need to make sure that all 3 words are present in the string.

Here are the words

advancebrain
com_ixxocart
p=completed

So as an example string you have 'blah blah sample text advancebrain where # com_ixxocart blah blahp=completedstuff' ? — Richard Parnaby-King, Mar 24 '11 at 15:59
Personally I'd do this with 3 regexes; it could be pretty ugly as just one, and probably slower. — Pointy, Mar 24 '11 at 15:59
Are these from a query string? If so, you might not need to use any regex — racerror, Mar 24 '11 at 16:03
I have to insert this into one input that google analytics gives me. So, I'm can only use one regex. — UpHelix, Mar 24 '11 at 16:14

score 20 · Accepted Answer · answered Mar 24 '11 at 15:58

20

Use lookahead assertions:

^(?=.*advancebrain)(?=.*com_ixxochart)(?=.*p=completed)

will match if all three terms are present.

You might want to add \b work boundaries around your search terms to ensure that they are matched as complete words and not substrings of other words (like advancebraindeath) if you need to avoid this:

^(?=.*\badvancebrain\b)(?=.*\bcom_ixxochart\b)(?=.*\bp=completed\b)

answered Mar 24 '11 at 15:58

Tim Pietzcker

297,146
54
452
522

I'm only given an input field to put this regex in, its for google analytics. They show their example of just a simple /yourregex/. Would you guess that lookahead will work? I don't know what programming language they will use to run the regex. – UpHelix Mar 24 '11 at 16:08
Looks like GA (Google Analytics) supports lookahead. http://www.lunametrics.com/blog/2007/08/08/regular-expressions-for-ga-bonus-iii-lookahead/ – UpHelix Mar 24 '11 at 16:14
is there a workaround for languages like go which does not support lookahead? – klew Jul 24 '20 at 11:15
@klew: You would need to hard-code all the possible permutations, so for a regex that checks if `a`, `b`, and `c` are present in any order, you'd need to search for `a.*b.*c|a.*c.*b|b.*a.*c|b.*c.*a|c.*a.*b|c.*b.*a`. – Tim Pietzcker Jul 24 '20 at 11:19
This of course is error-prone and scales horribly, so it's probably better to do three separate regex calls, one for each criterion, and make sure that all three match. – Tim Pietzcker Jul 24 '20 at 11:30

score 4 · Answer 2 · answered Mar 24 '11 at 16:18

4

^(?=.*?p=completed)(?=.*?advancebrain)(?=.*?com_ixxocart).*$

Spent too long testing and refining =/ Oh well.. Will still post my answer

answered Mar 24 '11 at 16:18

Richard Parnaby-King

13,858
11
64
123

score 1 · Answer 3 · answered Mar 24 '11 at 16:02

1

Use lookahead:

(?=.*\badvancebrain)(?=.*\bcom_ixxocart)(?=.*\bp=completed)

Order won't matter. All three are required.

answered Mar 24 '11 at 16:02

Tom

41
2

Better anchor the regex at the start, or you'll get horrible performance if not all three are present. – Tim Pietzcker Mar 24 '11 at 16:05

How to match multiple words in regex

3 Answers3

Linked