How to Generate Alphanumeric Codes

Question

I want to generate alphanumeric codes using C#.NET The first two digits should be alphabet The next two should be numeric and the last one should always be alphabet example: FR30T etc

Carl Schrader · Answer

Theo Here's one algorithm ... I doubt it is the best/most efficient out there; however it works. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication1 { class Program { static void Main( string [] args) { List string > alreadyHere = new List string >( new string [] { MA33I  ZZ22C  OO51A  YU13O  SX97Y }); Console .WriteLine( Alphanumeric generated code: 
	 + getAlphaNumericCode(alreadyHere) + 
 ); Console .ReadLine(); } private static readonly string template = __##_ ; static string getAlphaNumericCode( List string > codesAlreadyInUse) { Random alphaRandomGen = new Random ( DateTime .Now.Millisecond + DateTime .Now.Second); Random numericRandomGen = new Random ( DateTime .Now.Millisecond + DateTime .Now.Second); string sANCode = string .Empty; do { for ( int i = 0; i { int alphaChar = alphaRandomGen.Next(65 91); int numericChar = numericRandomGen.Next(48 58); if (template[i] == '_' ) sANCode += Encoding .ASCII.GetString( new byte [] { ( byte )alphaChar }); else sANCode += Encoding .ASCII.GetString( new byte [] { ( byte )numericChar }); } } while (codesAlreadyInUse.Contains(sANCode)); return sANCode; } } } Carl