Thread: functions return value

hi here is my code

Code:

#include<stdio.h>

int calc(int a, int b);

int main ()
{
     int first, second, answer;
     printf("pick two numbers: \n");
     scanf("%d", &first);
     scanf("%d", &second);
     answer = calc(first, second);
     if (calc(first, second) == 1)
          return 1;
     else
          printf("the result is: %d", answer);
     return 0;
}

int calc(int a, int b)
{
     if (b == 0)
     {
          printf("you cannot divide with zero");
          return 1;
     }
     else
          return (a/b);
}

when i type in i.e. 10 and 10 theres no output like
"the result is blabla". why that ?
and when i try to divide with zero the message
"you cannot divide with zero" is displayed twice. i dont really know whats wrong with my code.

i hope that someone can help me

thanks threadhead

You call the function twice, that's what causes your problems. It's better not to combine the error and good return values, do something like this.

Code:

#include<stdio.h>

int calc(int a, int b);

int main ()
{
    int first, second, answer;
    printf("pick two numbers: \n");
    scanf("%d %d", &first, &second);
    if (calc(first, second, &answer))
        return 1;
    else
        printf("the result is: %d", answer);
    return 0;
}

int calc(int a, int b, int *c)
{
    if (b == 0)
    {
        printf("you cannot divide with zero");
        return 1;
    }
    *c = a/b;

    return 0;
}

with that:

Code:

if (b == 0)
     {
          printf("you cannot divide with zero");
          return 1;
     }

i wanted to exit the function with return 1, what
means that there was an error during the function.
i thought 0 is going to tell the program that it can exit
and with 1 it can exit but knows that there was an error.
with

Code:

if (calc(first, second) == 1)
          return 1;

i wanted to check if the function calc exited normal or
with an error value like 1.
if so, main should exit with returning 1 to itself.

thanks