How to check and extract string via RegEx?

Question

I am trying to check if a string ends in "@something" and extract "something" from it if it does. For example, I am trying to do something like this:

string temp = "//something//img/@src"
if (temp ends with @xxx)
{
   string extracted = (get "src");
   ...
}
else
{
   ...
}

How can I accomplish this?

Answer 1

Try the following

var match = Regex.Match(tmp, @".*@(.*)$");
if ( match.Success ) { 
  var extracted = match.Groups[1].Value;
  ...

The trick here is the () in the regex. This groups the final matching into an unnamed group. This match can then be accessed via the Groups member on the Match variable by index. It's the first grouping so the index is 1

Answer 2

Don’t use a regular expression for this, it’s not worth it.

string temp = "//something//img/@src"
int pos = temp.LastIndexOf('@');
if (pos != -1)
{
   string extracted = temp.Substring(pos+1);
   ...
}
else
{
   ...
}

Answer 3

From your comments on my other answer, it appears what you need is something like this:

string temp = "//something//img/@src";
var match = Regex.Match(tmp, @"/@([\w]+)$", RegexOptions.RightToLeft);
if (match.Success)
{
   string extracted = match.Groups[1].Value;
   ...
}
else
{
   ...
}