using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"[a-zA-Z0-9](-?[a-zA-Z0-9])*(\.[a-zA-Z0-9](-?[a-zA-Z0-9])*)+";
string input = @"my-domain.com or sub.my-domain.com
my--domain.com or my-domain.com-net or my-domain-.com or etc must return false.";
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