using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^\s*(?:\+?(\d{1,3}))?[-. (]*(\d{3})[-. )]*(\d{3})[-. ]*(\d{4})(?: ?x(\d+))?\s*$";
string input = @"18005551234
1 800 555 1234
+1 800 555-1234
+86 800 555 1234
1-800-555-1234
1 (800) 555-1234
(800)555-1234
(800) 555-1234
(800)5551234
800-555-1234
800.555.1234
800 555 1234x5678
8005551234 x5678
1 800 555-1234
1----800----555-1234";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx