Here are some more Regex examples that may come in handy:
// Remove Html comments //html = Regex.Replace(html, @"\<!--[^>]*-->", ""); html = Regex.Replace(html, @"\<!--.*?-->", ""); // new version! // Validate an email address (with named groups) Regex regex = new Regex(@"^(?<user>[^@]+)@(?<host>.+)\..+$", RegexOptions.None); Match m = regex.Match(epost); /* Check m.Success to decide if valid or not */ // Validate a Swedish zip code ("postnummer") regex = new Regex(@"^(\d\d\d \d\d|\d\d\d\d\d)$", RegexOptions.None); m = regex.Match(postnummer);
In the first example, note .*? sequence. The question mark makes the match lazy, as opposed to the default greedy matching strategy. This makes a difference when there’s more than one comment in the html string. In my first try above I used [^>] to avoid matching the end comment marker, with the unfortunate side effect of missing comments with tags as content.
I have also found a useful online Regex testing service here:
(Update 2009-04-28: Changed service, the previous one is now unavailable…)