Converting space character in string to integer

Hi all. I am currently trying to write a program that implements the Ceasar cypher, which shifts all the letters in a message a certain number of letters forward. The way I am doing this is turning each letter into its ASCII number via static_cast-ing, doing a numerical formula to apply the shift, and then changing the new numbers back into letters to get the encrypted letter.
This worked fine for letters, but the problem is, I would like it to leave spaces (' ') alone, encrypting only letters themselves and leaving the spaces in the same spots. To do this, I say (where plaintext[i] is the original letter and cyphertext[i] is the new letter):

if (plaintext[i] == ' ')
cyphertext[i] = ' ';
else
//numerical formula for encrypting letters

However, it is not working at all. It ends up converting spaces into letters or symbols. Is there some wierd issue that I am not aware of forbidding comparisons with blank space? Any suggestions for how to fix this would be greatly appreciated. Thanks.

does it work if you compare it to 32, its decimal value

I already tried that, and it apparently never registered as being equal to 32 when I input spaces.

could you post as much relevant code (or all if not too much) for us to check out

Code:

---

for (int i = 0; i < len; ++i) {    //will cycle through all the letters of the message
        if (plaintext[i] == ' ') //ERROR HERE
            cyphertext[i] = ' ';
        else
            numtrans[i] = static_cast<int>(plaintext[i]);  //converts message letters to numbers
            numtrans[i] = ((numtrans[i] - 65 + keyshift) % 26) + 65;    //encyphers
            cyphertext[i] = static_cast<char>(numtrans[i]);    //converts back into letters, shifted
    }

---

This is the piece of code I used to convert letters to numbers, encode them, then convert back. The only actual error is in the second line, where I am checking to see whether plaintext[i] is a blank space, but the rest of the code is included because it might be relevant. Note: len is the length of the string plaintext, and numtrans is an integer array to hold the numerical values of the letters.

I tried replacing

Code:

---

if (plaintext[i] == ' ')

---

with

Code:

---

if (static_cast<int>(plaintext[i]) == 32)

---

but it did not help.

Wait all, I am sorry, I found the error in my code. It was actually fairly trivial. I just left out some brackets after the "else" statement above, but since the space was the only thing acting up, I thought that was the error. My code is working fine now.

For whatever reason, I was just writing a Caesar recently. FWIW as something to compare with:

Code:

---

#include <ctype.h>

/**
 * Encode text using a Caesar cipher. Only alphabetic characters are encoded,
 * and in their original case (upper or lower).
 *
 * @param  text  pointer to the text to encrypt
 * @param  shift  the number of characters to shift (must be less than 26)
 *
 * @return pointer to the encoded text
 *
 * @example
 * <pre>char text[] = "All work and no play makes Jack a dull boy.";
 * puts(text);            // "All work and no play makes Jack a dull boy."
 * puts(caesar(text, 3)); // "Doo zrun dqg qr sodb pdnhv Mdfn d gxoo erb."</pre>
 *
 * @note http://en.wikipedia.org/wiki/Caesar_cipher
 */
char *caesar(char *text, size_t shift)
{
    static const char alpha[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    char *start = text;
    size_t i, j;
    for ( i = 0; text[i]; ++i )
    {
        for ( j = 0; alpha[j]; ++j )
        {
            if ( toupper(text[i]) == alpha[j] )
            {
                char encoded = alpha[(j + shift) % (sizeof alpha - 1)];
                text[i] = islower(text[i]) ? tolower(encoded) : encoded;
                break;
            }
        }
    }
    return start;
}

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(C, of course.)