Why doesn't control enter the repeat() function?

Question

"Rewrite numbers from input to output. Stop processing input after reading in the number 42. All numbers at the input are integers of one or two digits."

#include <stdio.h>

int main() {
    int num ;

    int repeat()
    {  
        scanf("%d",&num) ;
        if(num!=42)
        {
             printf("\n%d",num) ;
             repeat() ;
        }
        else
        {
            return num ;
        }
        getch() ;
    }

    return 0;
}

@melpomene You can declare a function inside of another function. You cannot *define* one though. https://stackoverflow.com/questions/2608158/nested-function-in-c — Eugene Sh., Jan 25 '19 at 14:54
@melpomene Then what "not really" is related to? *Update:* Oh, I see, that it is inside it's own definition. Missed this point. — Eugene Sh., Jan 25 '19 at 14:55
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/187325/discussion-between-melpomene-and-eugene-sh). — melpomene, Jan 25 '19 at 14:55

alk · Answer 1 · 2019-01-25T15:20:44.887

Why do Control don't enter repeat() function?

Because main() does not call it.

The repeat() function is defined inside main(). Which is non standard. Moving it out makes things clearer:

#include <stdio.h>

int num ;

int repeat()
{  
    scanf("%d", &num);
    if(num != 42)
    {
        printf("\n%d", num);

        repeat();
    }
    else
    {
        return num ;
    }

    getch();
}

int main() {
    return 0;
}

From the above it is obvious that main() in fact does nothing.

score 0 · Answer 2 · answered Jan 25 '19 at 14:54

0

You created the function repeat() but you never call it Also you should pass num as an argument to repeat() and expect it to return.

answered Jan 25 '19 at 14:54

Michael Crowley

121
8

score 0 · Accepted Answer · answered Jan 25 '19 at 15:49

// Thanks for the help

#include <stdio.h>
int repeat(int num) 
    {  
        scanf("%d",&num) ;
        if(num!=42)
        {
               printf("%d",num) ;
               repeat(num) ;
        }
    else
    {
        return num ;
    }
    getch() ;
    }

int main() {
       int num ;
       scanf("%d",&num) ;
       repeat(num) ;
       return 0;
}

Why doesn't control enter the repeat() function?

3 Answers3