what is the regex for matching a string within two curly brackets as in
{{string}}
result should be string.
Do I have to escape both curly brackets?
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please provide more examples of what should and should not be matchedCode Jockey– Code Jockey2011-10-19 18:33:50 +00:00Commented Oct 19, 2011 at 18:33
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5 Answers
No, actually the following should work just fine:
"{{([^}]*)}}"
Edit:
As pointed out by dtb the expression above fails for a string containing a single } within the double brackets. To handle this case the following example would do a much better job:
"{{((?:}(?!})|[^}])*)}}"
Edit 2: The simplest solution however would probably be the following:
"{{(.*?)}}"
8 Comments
DeCaf
Very good point, thanks for pointing it out. Updated post with an expression that should take care of this scenario... I hope. ;)
Code Jockey
a much simpler adaptation would be to use
.*? instead of [^}]* - it will not consume the double }} because the ? makes the * reluctant, or lazyDeCaf
@CodeJockey: Apparently I shouldn't answer regex questions this late. Thanks for pointing that out!
Code Jockey
or possibly you should switch from decaf?
DeCaf
@CodeJockey: That I did years ago... didn't help much though, did it. ;)
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{{string}}
:p
or
{{(.*)}}
only numbers inside the {{ }}
{{([0-9])}}
only some characters:
{{([a-zA-Z])}}
Comments
I believe this would be the best/simplest possible regex to specifically capture the CONTENTS of the curly brackets:
(?<={{).*?(?=}})
Broken down, this says:
01 (?<={{) # match AFTER two open curly brackets
02 .*? # match anything, but BE LAZY ABOUT IT
03 (?=}}) # until there are two closing curly brackets
With this expression, the ENTIRE match will be the contents of the curly brackets, and the curly brackets will be left in place/ignored
To match the entire curly-bracketed expression, use the following:
01 {{ # match two open curly brackets
02 .*? # match anything, but BE LAZY ABOUT IT
03 }} # match two closing curly brackets
If you want to support multiple lines inside the curly brackets, use [\s\S]*? instead of .*? in the part on line 02, or specify the 'singleline' option for the regex parser (DOTALL in Java, etc, etc, etc...).
It does not reject instances like some text {{{inside}}} other test and may produce undesired results - if those are possible, please ask for a stronger expression and specify several cases of what should and should not be matched.
3 Comments
Alan Moore
It's
Singleline, not Multiline. Very common mistake--it comes of expecting the names to make sense. ;) As described here, Singleline changes the meaning of the . metacharacter, while Multiline changes the meaning of the anchors, ^ and $. Aside from that, this answer looks pretty good to me; not worthy of a downvote.Code Jockey
indeed - thanks for pointing that out... I would tend to agree about not being worthy of a downvote - but that's the way the cookie crumbles - just get a few people to agree with you and it will look a lot better!
Code Jockey
@Alan - that's also one possible downside of trying to provide a complete answer instead of a 'quick and dirty' answer - not only is it not available for people to read and vote on as long as fast draw answers, it might be more info than the asker needed or wanted, so they'll be here and gone before reading mine... sigh...
This should work:
resultString = Regex.Match(subjectString, @"^\{\{(.*?)\}\}$").Groups[1].Value;
Comments
string strRegex = @"{{(?<String>\w+)}}";
Regex myRegex = new Regex(strRegex);
string strTargetString = @"\n{{string}}";
var match = myRegex.Match(strTargetString);
string str = match.Groups["String"].Value;
The str variable will be the string from bracets
