/r/learnjava

import java.util.Scanner;
public class SecretMessages {

    public static void main(String[] args){

        String message;
        do{
            //ask the user for a message to encode or decode
            System.out.println("Enter a message to encode or decode ");

            Scanner scan = new Scanner(System.in);
            message = scan.nextLine();
            String out = "";

            System.out.print("Enter a secret Key (-26 to 26)");

            try{
                int intKey = Integer.parseInt(scan.nextLine());
                char key = (char)intKey;

                for (int x = 0; x <= message.length()-1; x++){

                    char in = message.charAt(x);

                    if (in >= 'A' && in <= 'Z'){
                        in += key;
                        if (in > 'Z'){
                            in -= 26;
                        }
                        if (in < 'A'){
                            in += 26;
                        }
                    }

                    if (in >= 'a' && in <= 'z'){
                        in += key;
                        if (in > 'z'){
                            in -= 26;
                        }
                        if (in < 'a'){
                            in += 26;
                        }
                    }

                        out += in;
                }
            } catch(Exception e){
                System.out.println("INVALID INPUT YOU CRETIN! Read the instructions!");
            }

            System.out.println();
            System.out.println(out);
            System.out.println();
            System.out.println("Do you want to encode/decode another message?(Y/N)");

            message =(String) scan.nextLine();
            message.toUpperCase();

            System.out.println();
        } while (!message.equals("N"));
    }

}