正则表达式忽略大括号

Question

{unknown string}  
{unknown string  
unknown string}
unknown string

How do I come up with a regex that recognizes just the string (which is unknown, so I cannot do an explicit match to a specific string) in all four of the above cases?

Answer 1

You haven't tried much, have you?

string result = Regex.Match(input, "hello").Value;

If you just want something between curly braces:

string result = Regex.Match(input, @"\{?(.*)\}?").Groups[1].Value;

Answer 2

\w+

It will match all "word"-characters

If you need to generalize it to something that's "between optional curly braces" you could use:

\{?(.+?)\}?

which means:

1. \\{? - an optional curly brace character. It's escaped because { has a special meaning in regular expressions. ? quantifier means 0 or 1 times (thus optional)
2. (.+?) - means anything in non-greedy mode. You need non-greedy here so that regex stops right before the following } (if any)
3. \\}? - the same as item #1