Encode or decode a message : Char : Data Types C# Source Code

    

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/


// Encode or decode a message. 
 
using System; 
  
public class Cipher { 
  public static int Main(string[] args) {   
 
    // see if arguments a present 
    if(args.Length < 2) { 
      Console.WriteLine("Usage: encode/decode word1 [word2...wordN]"); 
      return 1; // return failure code 
    } 
 
    // if args present, first arg must be encode or decode 
    if(args[0] != "encode" & args[0] != "decode") { 
      Console.WriteLine("First arg must be encode or decode."); 
      return 1; // return failure code 
    } 
 
    // encode or decode message 
    for(int n=1; n < args.Length; n++) { 
      for(int i=0; i < args[n].Length; i++) { 
        if(args[0]=="encode") 
          Console.Write((char) (args[n][i] + 1) ); 
        else  
          Console.Write((char) (args[n][i] - 1) ); 
      } 
      Console.Write(" "); 
    } 
 
    Console.WriteLine(); 
 
    return 0; 
  } 
}