Question

See the following function:

int go(void) {
   int *p, *q;
   p = calloc(10,sizeof(int));
   q = realloc(p, 20 * sizeof(int));
   <<X>>
}

Assuming that both memory allocation function calls are successful, which of the following statements are true at the point marker <<X>>.

1. The values of p and q are the same.
2. p points to 10 integers each with the value of 0.
3. q points to at least 80 bytes of memory.

This question is in my C test paper. Except for (2) which is obviously true. I’m quite confused about (1) and (3). Can anybody explain me this?

Answer 1

As Brendan said, (1) is not necessarily true (and probably not true).

In C, generally an “int” is 4 bytes, so (3) should be true. It is true on all systems that I know of, although I’m not positive that the C standard says that an “int” must be four bytes long.