Match and replace first and last character in string

Question

I would like to remove % characters from the start and the end of a string. For example:

string s = "%hello%world%";

Desired result: hello%world.

I know that I can fix this with some if cases combined with StartsWith(), EndsWith() etc. But I'm looking for a cleaner solution.

I suppose regexp is the way to go here, and that's where I need your help.

Answer 1

There's no need for a regular expression. Just use this:

string result = input.Trim('%');

But if you really need a regular expression, you'd need to use start (^) and end ($) anchors, like this:

string result = Regex.Replace(input, "^%|%$", "");