using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(\([11]{2,2}\)([ -\.]{0,1}[1]{1,1}[5]{1,1}[ -\.]{0,1}){0,1}[ -\.]{0,1}[0-9]{4,4}|\([0-9]{3,3}\)([ -\.]{0,1}[1]{1,1}[5]{1,1}[ -\.]{0,1}){0,1}[ -\.]{0,1}[0-9]{3,3}|\([0-9]{4,4}\)([ -\.]{0,1}[1]{1,1}[5]{1,1}[ -\.]{0,1}){0,1}[ -\.]{0,1}[0-9]{2,2})[ -\.]{1,1}[0-9]{4,4}$";
string input = @"(1212) 2354-1231
(1212)2354-1231";
foreach (Match m in Regex.Matches(input, pattern))
{
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