Non Capturing Groups
Expressions can contain a lot of groups which you weren't interested in matching on. It is possible to tell .net not to capture these by placing a ?: at the beginning of the group. Apparently limiting the number of capturing groups has a positive increase on performance.
The following expression will return one group, containing the entire match:
"(The door was (?:open|closed))"
This expression will also return one group, this time containing the state of the door; open or closed
"(?:The door was (open|closed))"
| Author |
: Paul Hayman |
| Published |
: Monday, 18 September, 2006 |
Paul is the COO of kwiboo ltd consultant and has more than a decade of IT consultancy experience. He has consulted for a number of blue chip companies and has been exposed to the folowing sectors: Utilities, Telecommunications, Insurance, Media, Investment Banking, Leisure, Legal, CRM, Pharmaceuticals, Interactive Gaming, Mobile Communications, Online Services.
Paul is the COO and co-founder of kwiboo (http://www.kwiboo.com/) and is also the creator of GeekZilla.