Question

Write a short program,Java, that implements the Caesar substitution cipher with k=3. That is, each letter in the input plaintext should be shifted by 3 positions (e.g., a is replaced by d, b is replaced by e, and so on). Please show code indentation, comments, and output.

Answer 1

import java.util.Scanner;

//CaesarShift3.java
public class CaesarShift3 {
    public static String encrypy(String code, int i)
    {
        String result = "";
        for(char ch: code.toCharArray()){
            ch = (char) (ch + i);
            if(ch > 'z'){
                ch = (char) ('a' + (ch%'z') - 1);
            }
            result += ch;
        }
        return result;
    }

    public static void main(String args[]){
        Scanner scan = new Scanner(System.in);
        String s;
        System.out.print("Enter text: ");
        s = scan.nextLine();
        System.out.println(encrypy(s,3));
    }
}