I'm working on a caesar cipher and I'm not exactly sure on how to go about it. I'm confused on how using the char type only stores one letter at a time and how to evaluate each letter, conver it into an interger?, then encrypt it, and display the new encrypted message.

This is what I have..



Obviously, this is terribly wrong. It doesn't even work after it displays "What interger would you like to use to shift?" It just ends the program. How do I do this exactly?

Oh this is completly wrong, the idea is there but it's not that simple, do not check my contributions if you're doing this as a solo project and learning C++(look it up when you're finished)

What you need is to have a copy of the ASCII table first of all :
ASCII table I use

The basic idea is to add the offset onto the character. The problem is that using the declaration char is going to be a problem since it holds a definite (if not one) letter. Your code converts the first letter.
*hint : use string.h*

Now for the encryption part :
My method was to use a different variable declared as int hence crypted

so I could use the original string in case I needed too or manipulate spaces (will be needed if the string includes it)

Now for the loop :
Use a for loop instead (will make the job easier) and use the
ch.length();. This value is the number of letters in the string (here ch). Make a separate variable and initialize to 0 then increment until the variable has reached ch.length();

Note : Once inside the loop, make sure you use ch[a]; and not ch; alone.

This way, the loop will process the whole string.

What if : x + 4 = | ?
You need to limit the alphabet inside the ASCII table :
The values you need are :
a = 97
z = 122
This part is more mathematical :


The basic idea of this is to get the overvalue, substract 'z' then add the result to 'a'.

I hope I haven't talked too much and perhaps gave you a headache but the answer is there ^^
I could post the code right now but I'd rather like you understand what I said.

I'd rather not do a string. I'd like to use the char type and be able to encrypt each individual letter of the input. Thank you though for the alternative! I still can't comprehend how to encrypt each letter into numeric value and back again by using a while loop. (I want to use a while loop..) It's just what I'm trying to figure out. Please help! Thanks.



It won't recognize the ch.length() function.

It won't recognize the ch.length() function because it does not exist...the .length() method is a method of the string class, which you have elected not to use.

Your ch variable has been declared as a single character...do you want it to be an array of characters?

To get the length of an array of characters, use the strlen() function.

If you do switch to the string class, you can still access each individual element for encryption.

How do I go about implementing that? Keep in mind, I honestly don't have any clue on how to get this code together. I'm looking for some basic code to convert and encrypt to get me started if that could be possible. Otherwise, more help in the right direction is always appreciative too. Thanks guys.

Append:

So, I've figured out how to encrypt a single letter in the Caesar Cipher, but I want to be able to do a whole word rather than a single letter.


Anyway, this works as long as you enter one letter. What type of loop would I need to use to evaluate an entire word, still using the char type for my variable that stores my password.

As mentioned, you can use a string object (or array of characters), and loop through it, encrypting as you go...below is a very quick and dirty example that demonstrates the functionality:

Please note this code is for demonstration purposes only...there is no error checking of any sort, nor does it take into account that you will want to ensure that you do not pass the final alphabetical character without beginning again.

To answer your other question, you can use almost any type of loop.

If you are absolutely intent on using the char type, then you need to realize that you require an array of characters...not a single char. See below...same caveats on the code - example of functionality only:

That code helped immensely. I still want to know how I can loop through a char variable and do the same thing with that. Is it possible?

I'm not sure I explained myself properly...a char variable is a single, meaning one, character...it holds ony one character. If you want to use several, you will require an array of characters, as per my second example...see above, and sorry for the confusion.

In other words


You can preferably use the for loop to initialize the "i" to 0, post the condition and increment althogether.

Amadeus's example uses the strlen() to record the number of characters inputted in the char array to set a condition (limit if you prefer)
(This prevents going through all the 80 spaces even 20 characters were inputted).
Since "i" starts out as 0, it will add the offset to all the characters in the array of char.

Now, what if you wanted to do this for two words? That is using string.

just keep running through the character array letter by letter encrypting each letter you come upon, and of course skipping spaces.

how do i skip the spaces?