Does increments (++i/i++) work differently in windows than linux?

Asked May 01 '15 at 16:25

Active May 01 '15 at 16:25

Viewed 48 times

I am having some trouble figuring out why this code is showing different results in linux and windows:

#include <stdio.h>

int main()
{
    int x=2;
    x = 4 * x++;
    printf("%d\n", x);

    return 0;
}

In linux it is showing 8 (which is logically correct I think). In windows it is showing 9. Is it because the increment is done after the statement is finished executed rather than when evaluating? The same thing happens for pre-increments.

NB: In linux I am using gcc, in windows I am using mingw (codeblocks).

asked May 01 '15 at 16:25

emnoor

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I tried with gcc version 4.7.2 under linux (Debian 4.7.2-5). It returns 9, not 8. – Michel Billaud May 01 '15 at 16:29
1

Because different devs have different considerations when implementing **defined behaviours**, resulting in different **undefined** ones. – Eugene Sh. May 01 '15 at 16:30
1

Actually, the undefined behaviour is detected by the -Wall option of the gcc compiler – Michel Billaud May 01 '15 at 16:33
So that's the reason. And may be it is the newer gcc (mine is 4.9.3) that the behaviour is changed, not because of the OS. :| – emnoor May 01 '15 at 16:50
And I didn't know that it is an undefined behaviour. Thanks @MichelBillaud – emnoor May 01 '15 at 16:51

Does increments (++i/i++) work differently in windows than linux?

0 Answers0