Small regex exclude problem.

Question

Guys i have a small and frankly stupid problem, so here it is...

I have a text that could possibly include words,numbers etc. All i want is to match the numbers inside brackets, but withtout matching them like this:

Lorem 43 ipsum dolor 1 sit amet (355) some other text.

All i want to match is the number 355, but since there are numbers without brackets, i get to this:

\(\b\d+\b\) - 1st variant
\(.+?\)     - 2nd variant

presumably i get (355), but my php script is already under heavy load, matching to remove the brackets is not a n option.

Answer 1

Just match like your 1st variant, but capture only the digits in a group, like this

\((\d+)\)

And I think PHP supports named capture groups, so you could name it, so you aren't looking it up by index, like this I think

preg_match('/\((?<MatchedNumber>\d+)\)/', $searchText, $groups);
print_r($groups['MatchedNumber']);

Answer 2

If you like you can remove the \b's in the first one; they don't hurt anything but they're redundant. To capture the number and exclude the parentheses, use unescaped parentheses around the digits:

\((\d+)\)

This will capture the digits for later use. For example:

preg_match('/\((\d+)\)/', $sentence, $matches);
var_dump($matches[1]);