using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"\bMobile:\s*\K\d{3}([ -]?)\d{3}\1\d{4}\b";
string input = @"Phone: 111-111-1111 e1t. 215 => return Empty
Phone: 111-111-1111 Mobile: 911-111-1000 => return 911-111-1000
Mobile: 911-111-1000 Phone: 111-111-1111 => return 911-111-1000
Phone: 111-111-1111 Mobile: 911 111 1000 e1t. 215 => return 911-111-1000
Mobile: 911-111-1000 Phone: 111-111-1111 e1t. 215 => return 911-111-1000
Phone: 111-111-1111 e1t. 215 Mobile: 9111111000 => return 911-111-1000";
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