Function logic error

[Mentallic]

The relevant part of my code:

#include <stdio.h>

int getSize(void);
void errorReport(int size);

int main(int argc, char *argv[]) {
    int size = 0;
    
    size = getSize();
    printf("In main, size = %d\n", size);

    return 0;
}

int getSize(void) {
    printf("Enter the grid size, an odd number between 3 and 15: ");
    int size = 0;
    scanf("%d", &size);
    printf("In getSize 1, size = %d\n", size);
    errorReport(size);
    printf("In getSize 2, size = %d\n", size);
    return size;
}

void errorReport(int size) {
    if ( (size < 3) || (size > 15) || ((size % 2) == 0) ) {
        getSize();
    }
}

What it should be doing is first prompting the user,

Enter the grid size, an odd number between 3 and 15:

And if the user enters an invalid number, it'll just ask again. Once the user enters a valid number it should then assign it to the variable size and pass it back into the main function.

However, here is some input and the output when I run the code:

Enter the grid size, an odd number between 3 and 15: 2
In getSize 1, size = 2
Enter the grid size, an odd number between 3 and 15: 4
In getSize 1, size = 4
Enter the grid size, an odd number between 3 and 15: 100
In getSize 1, size = 100
Enter the grid size, an odd number between 3 and 15: 5
In getSize 1, size = 5
In getSize 2, size = 5
In getSize 2, size = 100
In getSize 2, size = 4
In getSize 2, size = 2
In main, size = 2

Notice that it's keeping the incorrect values I entered previously and so the value of size being passed into the main function is the first value I entered.

I just don't understand why it's doing this...

[Salem]

errorReport calls getSize, but ignores the return result.

You're better off putting an actual loop in getSize(), and make errorReport() return a simple boolean indicating whether size is OK or not.
If it's OK, you return from getSize(), otherwise you loop for another value.

[Mentallic]

I changed my code to

int getSize(void) {
    printf("Enter the grid size, an odd number between 3 and 15: ");
    int size = 0;
    scanf("%d", &size);
    printf("In getSize 1, size = %d\n", size);
    int fail = 0;
    fail = errorReport(size);
    if (fail == 1) {
        getSize();
    }
    printf("In getSize 2, size = %d\n", size);
    return size;
}

//Check if the size entered is valid
int errorReport(int size) {
    int fail = 0;
    if ( (size < 3) || (size > 15) || ((size % 2) == 0) ) {
        fail = 1;
    }
    return fail;
}

But I'm still getting the same result. Also, I don't quite understand what you mean by the errorReport function calling getSize but ignoring the return result? If only I had an intuitive understanding of what these functions are doing, then maybe I'd be able to see what was going wrong.

[Salem]

A recursive call is not the kind of loop you want.

do {
  // some stuff here
} while ( fail != 0 );

[Mentallic]

Sorry, but I can't see how to apply your suggestion, could you please clear things up a little bit?
I don't understand why the previous values of size are being kept, I thought they would be overridden...

[Salem]

Either of these would work.

int getSize(void) {
    printf("Enter the grid size, an odd number between 3 and 15: ");
    int size = 0;
    scanf("%d", &size);
    printf("In getSize 1, size = %d\n", size);
    int fail = 0;
    fail = errorReport(size);
    if (fail == 1) {
        size = getSize();
    }
    printf("In getSize 2, size = %d\n", size);
    return size;
}

int getSize(void) {
    printf("Enter the grid size, an odd number between 3 and 15: ");
    int size = 0;
    int fail = 0;
    do {
        scanf("%d", &size);
        printf("In getSize 1, size = %d\n", size);
        fail = errorReport(size);
    } while ( fail != 0 );
    printf("In getSize 2, size = %d\n", size);
    return size;
}

[Mentallic]

In the first one, the only difference was that you replaced getSize() with size = getSize(). I'll try to keep this procedure in mind so I don't trip over it again in the future.

I didn't know do was a loop function, in your previous post I thought you were literally telling me to do something lol.

Thanks Salem, you've been a great help!