Csharp/C Sharp by API/System.Text.RegularExpressions/Regex

new Regex(String pattern)

<source lang="csharp">

using System; using System.Text.RegularExpressions; class MainClass {

   public static void Main()
   {
       string s = "A, B,cCCC, D";
       Regex regex = new Regex(@" |, ");
       foreach (string sub in regex.Split(s))
       {
           Console.WriteLine("Word: {0}", sub);
       }
   }

}

 </source>

Regex.CompileToAssembly

<source lang="csharp"> using System; using System.Reflection; using System.Text.RegularExpressions; class MainClass {

   public static void Main() {
       RegexCompilationInfo[] regexInfo = new RegexCompilationInfo[2];
       regexInfo[0] = new RegexCompilationInfo(@"^\d{4}$", RegexOptions.rupiled, "PinRegex", "", true);
       regexInfo[1] = new RegexCompilationInfo(@"^\d{4}-?\d{4}-?\d{4}-?\d{4}$", RegexOptions.rupiled, "CreditCardRegex", "", true);
       AssemblyName assembly = new AssemblyName();
       assembly.Name = "MyRegEx";
       Regex.rupileToAssembly(regexInfo, assembly);
   }

}

 </source>

Regex.IsMatch

<source lang="csharp"> using System; using System.Collections.Generic; using System.Globalization; using System.Text; using System.Text.RegularExpressions; using System.Reflection; public class MainClass{

  public static void Main(){
       Regex r = new Regex("^\\d+");
       
       
       string[] ss = new string[] { "123abc", "abc123", "123", "abc", "a123bc" };
       foreach (string s in ss)
          Console.WriteLine(r.IsMatch(s));
  }

}

 </source>

Regex.Match

<source lang="csharp"> using System; using System.Collections.Generic; using System.Globalization; using System.Text; using System.Text.RegularExpressions; using System.Reflection; public class MainClass{

  public static void Main(){
       Regex r1 = new Regex(@"((abc)*)x(\1)");
       string s1 = "abcabcabcxabc";
       Console.WriteLine(r1.IsMatch(s1) + "..." + r1.Match(s1).Value);
  }

}

 </source>

Regex.Match(String value,String pattern).Success

<source lang="csharp"> using System; using System.Text.RegularExpressions; class RegexSubstitution {

  public static void Main()
  {
     string text = "Name";
     if ( !Regex.Match(text,"^[A-Z][a-zA-Z]*$" ).Success )
     {
        Console.WriteLine( "Invalid last name");
     }
  }

}

 </source>

Regex.Replace

<source lang="csharp"> using System; using System.Text; using System.Text.RegularExpressions; public class MainClass {

   static void Main( string[] args ) {
       // Create regex to search for IP address pattern.
       string pattern = @"(?<part1>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                        @"(?<part2>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                        @"(?<part3>[01]?\d\d?|2[0-4]\d|25[0-5])\." +
                        @"(?<part4>[01]?\d\d?|2[0-4]\d|25[0-5])";
       Regex regex = new Regex( pattern );
       Match match = regex.Match( "192.168.123.1" );
       string replace = @"${part4}.${part3}.${part2}.${part1}" +
                        @" (the reverse of $&)";
       Console.WriteLine( regex.Replace("192.168.123.1", replace) );
   }

}

 </source>

Regex.Split

<source lang="csharp"> using System; using System.Text.RegularExpressions;

public class MainClass {

   public static void Main() {
       string x = "Once Upon A Time In America";
       Regex m = new Regex("( )");
       foreach (string ss in m.Split(x)) {
           Console.WriteLine(ss);
       }
   }

}

 </source>