Question

I don’t know anything about regular expressions but I think I have to use it for my probleme I got some filenames that look like :

MyResource
MyResource.en-GB
MyResource.en-US
MyResource.fr-FR
MyResource.de-DE

The idea is to test if my strings end with “[letter][letter]-[letter][letter]”

I know this is a very noob, but I just have no idea about how to do it, even if I know exactly what I wanna do… 🙁

Answer 1

That would be testing your input against:

\.[a-z]{2}-[A-Z]{2}$

This is really very literal: “match a dot (\., the dot being a special character in regexes), followed by exactly two of any characters from a to z ([a-z]{2} — [...] is a character class), followed by a dash (-), followed by two of any characters from A to Z ([A-Z]{2}), followed by the end of input ($).

http://www.dotnetperls.com/regex-match <– how to apply this regex in C# against an input. It means the code would look like (UNTESTED):

// Post edit: this will really return a boolean
if (Regex.Match(input, @"\.[a-z]{2}-[A-Z]{2}$").Success) {
    // there is a match
}

http://regex.info <– buy that and read it, it is the BEST resource for regular expressions in the universe

http://regular-expressions.info <– the second best resource