Caesar Cipher

caesar-cipher.cs

using System;

namespace CaesarCipher
{
  class Program
  {
    static void Main(string[] args)
    {
      Console.Write("Enter your secret message: ");
      string input = Console.ReadLine();
      char[] secretMessage = input.ToCharArray();

      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'};
      char[] encodedMessage = new char[secretMessage.Length];

      for (int i = 0; i < secretMessage.Length; i++)
      {
        char letter = secretMessage[i];
        int letterPosition = Array.IndexOf(alphabet, letter);
        int newLetterPosition = (letterPosition + 3) % alphabet.Length;
        char letterEncoded = alphabet[newLetterPosition];
        encodedMessage[i] = letterEncoded;    
      }

      string encodedString = String.Join("", encodedMessage);
      Console.WriteLine($"Your encoded message is: {encodedString}");
    }
  }
}