Scala implementation of the Caesar Cipher

caesar_chipher.scala

//Ceasar (Shift) Cipher
//Pedro Miguel Sosa
//www.KonukoII.com
//Tutorial & Explanation: http://konukoii.com/blog/2016/03/24/caesar-cipher-in-scala/

object CeasarCipher extends App{

	//Define Alphabet
	//feel free to add more elements to your 'alphabet' (eg. Nums: 123... or Symbols: !?@#...)
	val alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"


	//We will shift our plaintext by this much
	//Notice: shift = (# + 26) % 26 <-- This allows us to take any number (even if it is negative, or bigger than our alphabet size) 
	val shift = (scala.io.StdIn.readLine("Shift By: ").toInt + alphabet.size) % alphabet.size

	//What is the code we want to encrypt/decrypt
	val inputText = scala.io.StdIn.readLine("Secret Message: ")

	//Lets Encrypt/Decrypt the code
	val outputText = inputText.map( (c: Char) => { 

		//We find the c char in our allowed alphabet
		val x = alphabet.indexOf(c.toUpper)

		//If the c char is in our alphabet then we encrypt it 
		//If it is not then we leave it be.
		if (x == -1){
			c
		}
		else{
			alphabet((x + shift) % alphabet.size)
			} 
	});

	//Print the result
	println(outputText);
}