Shashidhara S Bapat wrote:
Hi All, I have doubts in the following C program: (I used gcc compiler)
>>> #include <stdio.h>
int main() { int i, j, b;
i = 12, j = 1; b = ++i + ++i + i++;
Refrain from using such expressions as they are Undefined in ANSI. You Cannot be sure of the answer (i.e. it can vary from compiler to compiler and hence is not portable).
printf("%d\n", b);
i = 12, j = 1; b = j++ + ++j;
Read Above
printf("%d\n", b);
i = 12, j = 1; b = ++i + ++i + i++ + j++ + ++j ;
RE-READ above
printf("%d\n", b);
return 0; }
and the output of the code is : 42 4 45.
..and my question is why do we get 42 in the first printf? (I was expecting 41 (13+14+14) O:-) ) and in the second printf why it isn't 3?
(If it is because of the usage of stack (and/or tree) during the evaluation of those expressions, why dont we get 46 in the 3rd printf (42 + 4) ?).
Does it depend on the compiler? Please let me know abt the reason.
UNDEFINED BEHAVIOUR
thanks in advance.
