How do I take sentences as an input in this case?

Question

Caesar Cipher Code : The code is not letting me input any sentences or strings with spaces even when i am using sc.nextLine(), neither is it giving an error. JUST BLANK.


import java.util.*;

public class CaesarCipher
{
    protected char[] encoder = new char[26];
    protected char[] decoder = new char[26];

    /** Constructor that initializes the encryption and decryption arrays */
    public CaesarCipher(int rotation)
    {
        for(int k=0;k<26;k++)
        {
            encoder[k] = (char)('A' + (k + rotation)%26);
            decoder[k] = (char)('A' + (k - rotation+26)%26);
        }
    }

    /** Returns String representing encrypted message. */
    public String encrypt(String message)
    {
        return transform(message,encoder);
    }

    public String decrypt(String Secret)
    {
        return transform(Secret, decoder);
    }

    public String transform(String Original,char[] code)
    {
        char msg[] = Original.toCharArray();

        for(int k=0;k<msg.length;k++)
        {
            if(Character.isUpperCase(msg[k]))
            {
                int j = msg[k] - 'A';
                msg[k] = code[j];
            }
        }
        return new String(msg);
    }

    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);

        System.out.println("Enter any number between 1 and 26 : ");
        int r = sc.nextInt();
        System.out.println();

        CaesarCipher cipher = new CaesarCipher(r);

        System.out.println("Encryption code : " + new String(cipher.encoder));
        System.out.println("Decryption code : " + new String(cipher.decoder));
        System.out.println();

        System.out.println("Enter a Message to Encrypt : ");
        String message = sc.nextLine();

        String coded = cipher.encrypt(message.toUpperCase());
        System.out.println("Encrypted Message : " + coded);
        System.out.println();

        System.out.println("Decrypted Message : " + cipher.decrypt(coded));
        sc.close();
    }

}

Output :

Enter any number between 1 and 26 : 4

Encryption code : EFGHIJKLMNOPQRSTUVWXYZABCD Decryption code : WXYZABCDEFGHIJKLMNOPQRSTUV

Enter a Message to Encrypt : Encrypted Message :

Decrypted Message :

score -1 · Answer 1 · answered Oct 02 '22 at 17:38

You have to feed your next line \n to the Scanner object and then start writing something yourself.

Like this:

System.out.println("Enter a Message to Encrypt : ");
sc.nextLine(); // Next line is "eaten" here
String message = sc.nextLine(); // Program halts and waits for your msg

You can find more info here.

How do I take sentences as an input in this case?

1 Answers1