Caesar Cipher Example - Completed Project with Extensions

using System;

namespace CaesarCipher

{

  class Program

  {

    public static class Globals

    //This makes it so the alphabet array can be accessed in multiple methods so it doesn't need to be defined each time.

    {

      public static char[] alphabet = new char[] {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};

    }

    static void Encrypt()

    {

      Console.WriteLine("What secrets ye' hold?");

      string rawMessage = Console.ReadLine().ToLower();

      //This makes it so your user input is automatically percieved in lower case.

      char[] secretMessage = rawMessage.ToCharArray();

      char[] encryptedMessage = new char[secretMessage.Length];

      for (int i = 0; i < secretMessage.Length; i++)

      {

        char fehu = secretMessage[i];

        bool alpha = Char.IsLetter(fehu);

        //This checks if the lettter being checked is a letter or not.

        if (alpha == true)

        //If it is a letter, the program runs normally.

        {

        int uruz = Array.IndexOf(Globals.alphabet, fehu);

        int thurisaz = (uruz += 3) % Globals.alphabet.Length;

        char ansuz = Globals.alphabet[thurisaz];

        encryptedMessage[i] = ansuz;

      }

      else

      //This leaves non-letters unaltered.

      {

        encryptedMessage[i] = secretMessage[i];

      }

      }

      string transcription = String.Join("", encryptedMessage);

      Console.WriteLine(transcription);

          }

          static void Decrypt()

          //This is the same exact code as the encryption except for the greeting message and...

           {

      Console.WriteLine("What have you heard?");

      string rawMessage = Console.ReadLine().ToLower();

      char[] secretMessage = rawMessage.ToCharArray();

      char[] encryptedMessage = new char[secretMessage.Length];

      for (int i = 0; i < secretMessage.Length; i++)

      {

        char fehu = secretMessage[i];

        bool alpha = Char.IsLetter(fehu);

        if (alpha == true)

        {

        int uruz = Array.IndexOf(Globals.alphabet, fehu);

        int thurisaz = (uruz -= 3) % Globals.alphabet.Length;

        //The second difference, where you subtract 3 instead of adding it.

        char ansuz = Globals.alphabet[thurisaz];

        encryptedMessage[i] = ansuz;

      }

      else

      {

        encryptedMessage[i] = secretMessage[i];

      }

      }

      string transcription = String.Join("", encryptedMessage);

      Console.WriteLine(transcription);

          }

    static void Main(string[] args)

    {

      string beta = "";

      // Defining the variable for whether you want something encrypted or decrypted.

      Console.WriteLine("Do you speak, or do you listen?");

      // Lets the user decide if they're encrypting or decrypting.

      beta = Console.ReadLine().ToLower();

      if (beta == "speak")

      {

        Encrypt();

      }

      else if (beta == "listen")

      {

        Decrypt();

      }

  }

}

}