Thread: Ceasar Cipher

I'm in an intro to programming class and while I'm able to follow along with basic problems, I totally don't get some of the problems that get assigned as homework. I've spent an inordinate amount of time trying to just figure out how to started on what I've come to realize (after looking at literally every google search possible related to this) is a very simple problem. I just don't know how to get the ball rolling here. I basically just need to make a program that takes a cipher inputted by the user and moves all the characters in that cipher "up" 3 characters [i.e. D (68 as I understand it is interpreted in computer language) goes to A (65)]. I realize it's supposedly really simple but I have literally no idea how to do it.

Can someone give me like a pseudocode or something so I can see the basic framework? The full code would be great as well but I really want to wrap my head around this stuff and I think seeing it in a language I can actually understand might do a lot to help. Any and all assistance would be extremely appreciated.

No one will do it for you. And you will most likely be asked to have a fair go yourself before being offered assistance.

Try writting out the steps yourself first. Post them up and ask direct questions. You will be more inclined to have someone offer their time when you show your own commitment.

It is pretty easy and I'm sure we can get you there pretty quickly.

Remember if you post actual code to use the appropriate formatting tags.

You won't be ridiculed for trying.

Listen I understand the whole not wanting to do someone's homework sentiment. I just have no idea where to even start -- what classes, methods or whatever to use.

If I had to write it in plain regular english it would simply be something that asked the user to input the encrypted cipher, then took that input, shifted each of the letters 3 places up individually, and then spit out the result. That simple. The problem is I don't know to design that letter-shift mechanism.

Let me rephrase my question then: can someone show me how to write that letter shifting mechanism? Or, if that is too much to do, just give me the key java terms I would need so I can look them up in my textbook?

Originally Posted by programnovice

something that asked the user to input the encrypted cipher, then took that input, shifted each of the letters 3 places up individually, and then spit out the result. That simple.

Step 1: ask user for input
Step 2: shift the input one character at a time
Step 3: spit out the result

Take the steps you have listed and refine them more and more, until they seem like such a simple task. When you focus on writing many codes to solve many small problems, you will no longer be trying to write one code to solve a big problem.
When you get the steps broken down and run into a problem, post your steps, what you are stuck on, and what code you have so far with your question.

Okay, good one.

String API 7, look at the method tochararray(). It basically takes a string and explodes it into an array of chars. Once you have those, manipulation becomes easier.

Run this in your IDE and understand what is happening. See what you can come up with.

public class Sandbox {
 
    public static void main(String[] args) {
 
        //Initial string
        String hello = "Hello";
 
        // Explode the string into an array of chars
        char[] charArray = hello.toCharArray();
 
        // Print the array as a string
        System.out.println(String.valueOf(charArray));
 
        // Print each character of the array
        for (int i = 0; i < charArray.length; i++) {
            System.out.print(charArray[i] + ", ");
        }
 
    }
}

Hello.
Based on your writing the only solution is to give you a ready-made program.
Otherwise you need to learn java step by step and write your program.
In my opinion its very hard to give you any starting point.

Syed.