Question

I am trying to write a regular expression to match a form of string :

"[A-Za-z][A-Za-z]-[A-Za-z][A-Za-z]_[match all chars]"

The string I want to match must be of this form, including the hyphen and underscore. So far I have :

Regex regEx = new Regex(@"[A-Za-z]+(-[A-Za-z]+)+*$", RegexOptions.IgnorePatternWhitespace);

I am not sure how to add in the underscore character so that this is matched.

This element is an XML element I wish to match; I would also like to retrieve the contents of this element. How could I do this ?

var newVar = from e in doc.Descendants("DocumentElement").Descendants() 
                         where regEx.IsMatch(e.Name.LocalName) 
                        select e;

Answer 1

I’d use

@"^[A-Za-z]{2}-[A-Za-z]{2}_.*$"

Explanation:

• ^ beginning of the line
• [A-Za-z]{2} exactly 2 characters must be a-zA-Z
• - the dash
• _ the underscore
• .* any character
• $ end of the line

EDIT:

See also Regex docs