Simple Cipher Program

Hello everyone, i am in the beginning stages of creating my own caesar cipher and i am running into trouble with my cipher array.

If you run the program below and just input something simple like "my name is john doe" . "array" returns what it is supposed to, but "cipher" returns the encrypted message plus some other garbage as shown below:
"p|qdphlvu|dq�Rп���ȁ�Rп�".

What can i do to correct this?

here is the code:

Code:

---

#include <stdio.h>
#include <string.h>

#define MAX 100

main()
{
        char array[MAX], cipher[MAX];
        int i, x, c;
        i = x = 0;
        while((c=getchar()) != '\n')
        {
                array[i] = c;
                cipher[x] = (int) c + 3;
                x++;
                i++;
        }
        printf("%s\n", array);
        printf("%s\n", cipher);
}

---

You have to init your char arrays from garbage to clean empty fills of zeros

Code:

---

#include <stdio.h>

int main() {
        char array[100]={0}, cipher[100]={0};

        int c;
        while((c=getchar()) != '\n') {
                static int x=0, i=0;

                array[i++]=(char)c;
                cipher[x++]=(char)(c+3);
        }

        printf("&#37;s\n",cipher);

        return 0;
}

---

wow, that was quick!

thanks for the insight, much appreciated :)

Well the best way is to just init your char array to 0 as I did.
edit: np :)

It's not really necessary to initiate the arrays to zero.

You just need to NUL terminate the string.

Quote:

---

Originally Posted by MeTh0Dz

It's not really necessary to initiate the arrays to zero.

You just need to NUL terminate the string.

---

is this what you mean?


cipher[x++] = '\0'

Quote:

---

Originally Posted by MeTh0Dz

It's not really necessary to initiate the arrays to zero.

You just need to NUL terminate the string.

---

It might not be necessary but if you do init char arrays, there is no need to worry about their usage later when it comes to this kind of problem.

Quote:

---

Originally Posted by PunchOut

is this what you mean?


cipher[x++] = '\0'

---

This is the way he/she proposed:

Code:

---

#include <stdio.h>

int main() {
        char array[100], cipher[100];
        int c=0, x=0, y=0;

        while((c=getchar()) != '\n') {
                array[x++]=(char)c;
                cipher[y++]=(char)(c+3);
        }

        array[x]=0;
        cipher[y]=0;

        printf("&#37;s\n",cipher);

        return 0;
}

---

you need to add the size limit check - to prevent writing beyong bounds of the arrays