what is wrong with this code ? can anyone explain ?
#include <stdio.h>
#include <malloc.h>
#define TOTAL_ELEMENTS (sizeof(array) / sizeof(array[0]))
int array[] = {23,34,12,17,204,99,16};
int main()
{
int num;
int d;
int size = TOTAL_ELEMENTS -2;
printf("%d\n",(TOTAL_ELEMENTS-2));
for(d=-1;d <= (TOTAL_ELEMENTS-2);d++)
printf("%d\n",array[d+1]);
return 0;
}
when i print it gives 5, but inside for loop what is happening ?
The sizeof operator returns a value of type size_t, which is an unsigned value. In your for loop condition test:
d <= (TOTAL_ELEMENTS-2)
you are comparing a signed value (d) with an unsigned value (TOTAL_ELEMENTS-2). This is usually a warning condition, and you should turn up the warning level on your compiler so you'll properly get a warning message.
The compiler can only generate code for either a signed or an unsigned comparison, and in this case the comparison is unsigned. The integer value in d is converted to an unsigned value, which on a 2's complement architecture ends up being 0xFFFFFFFF or similar. This is not less than your TOTAL_ELEMENTS-2 value, so the comparison is false.
(size_t)-1 is always SIZE_MAX.You're starting the loop by setting d = -1, it should be d = 0. So for the first element you're reading random bits of memory.
If you fix that, then you can change your printf to be
printf("%d\n",array[d]);
As you've also marked this as homework, I'd advise also take a look at your loop terminating condition.
