None capturing group (?:...)
Q
Is there any to stop capturing a group to improve matching performance?
How to write a possessive quantified subpattern to match double-quoted strings like this: "He said: \“Hello!\”"?
✍: FYIcenter.com
A
Yes. To turn the default capturing behavior on a group, you can entered '?:' at the beginning of the group as (?#:...). For example:
qua(1|nt)ifier # matches both 'qualifier' and 'quantifier' qua(?:1|nt)ifier # matches both words, but no capturing
The regular expression to match double-quoted strings efficiently is:
"(?:[^"\]++|\.)*+"
(?:...) - non-capture grouping
[^"\]++ - repeat [^"\] 1 or more times without backtracking
\. - any character escaped by \
(...)*+ - repeat (...) 0 or more times without backtracking
2013-01-26, 2162👍, 0💬