Question

I recently did an assignment using bit masking and shifting to manipulate a 4 byte int.

I got to wondering if it was possible to set a char pointer to the start of the int variable and then step through the int as if it was a 1 byte char by using the char pointer.

Is there a way to do this or something similar? I tried to set the char pointer to an int but when I step ahead by 1 it jumps 4 bytes instead.

Just trying to think of alternative ways of doing the same thing.

Answer 1

Of course you can, this code shows the behavior:

#include <stdio.h>

int main()
{
  int value = 1234567;
  char *pt = (char*) &value;

  printf("first char: %p, second char: %p\n", pt, pt+1);
}

This outputs:

first char: 0x7fff5fbff448, second char: 0x7fff5fbff449

As you can see difference is just 1 byte as intended, this because arithmetic on pointers has been done after casting the type to a smaller kind of data.