C, post-decrement in operation

Asked Feb 15 '14 at 12:36

Active Feb 15 '14 at 12:41

Viewed 42 times

I've got a code like this:

#include <stdio.h>

main() {
    int a=3,b=8;
    b=(b--)*a;
    printf("%i", b);
    getch();
}

A compiler return 24 for b, and another one 23 (dev c++, first version 4.9.9.2 and the other with dev c++ version 5.x).

What's the right? And why?

Thanks.

edited Feb 15 '14 at 12:41

AliciaBytes

asked Feb 15 '14 at 12:36

Kripto

2

Both are right (or wrong, howsoever you want to put it). This is undefined behavior. – devnull Feb 15 '14 at 12:39
If I'm not mistaken, Undefined Behaviour. You should avoid doing so. – frp Feb 15 '14 at 12:40
(b--)*a should return 24, it becomes an undefined behaviour if you assign it to b. – Arpit Singh Feb 15 '14 at 12:49

0 Answers0