Find and extract a number from a string

\d+ is the regex for an integer number. So

//System.Text.RegularExpressions.Regex
resultString = Regex.Match(subjectString, @"\d+").Value;

returns a string containing the first occurrence of a number in subjectString.

Int32.Parse(resultString) will then give you the number.

Here's how I cleanse phone numbers to get the digits only:

string numericPhone = new String(phone.Where(Char.IsDigit).ToArray());