using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(?<firstchar>(?=[A-Za-z]))((?<alphachars>[A-Za-z])|(?<specialchars>[A-Za-z]['-](?=[A-Za-z]))|(?<spaces> (?=[A-Za-z])))*$";
string input = @"#First Name must contain letters only. It may contain spaces, hyphens, or apostrophes.
First name-and hy-phen's
#It must begin with letters.
First name
1shouldn't match
'shouldn't match
#All other characters and numbers are not valid.
Should match
Should not m@tch
Should not m#tch
#Special characters ‘ and – cannot be together (e.g. John’-s is not allowed)
Allow'd
NotAllow-'d
NotAllow'-d
#An alphabet should be present before and after the special characters ‘ and – (e.g. John ‘s is not allowed)
Allow'd
Also A'llowed
A'llowd
Not Allowd'
Not 'Allowd
#Two consecutive spaces are not allowed (e.g. Annia St is not allowed)
";
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