Extract values within single curly braces

Question

I want to get a collection {value} of a string using Regular Expression .

For example:

lorem ipsum {field1} lorem ipsum {field2} lorem ipsum field1 lorem ipsum field2 {{field3}}

I would get: {field1} and {field2}

I try this:

string pattern =@"\[(?>[^\{\}]+)*\]";

MatchCollection matches = Regex.Matches(text, pattern);
for (int ctr = 0; ctr < matches.Count; ctr++)
{
    string field = matches[ctr].Value;
    // ... ommitted...
}

Any suggestions?

Answer 1

You can use negative lookarounds to only get the {...} substrings not having { in front or } right after them:

(?<!{){[^{}]+}(?!})

See the regex demo

• (?<!{) - a negative lookbehind failing the match if there is a { before the current position
• { - a literal {
• [^{}]+ - 1 or more symbols other than { and }
• } - a literal }
• (?!}) - a negative lookahead failing the match if there is } right after the previous } .