The C Programming Language - Pointers

Pointers, or rather pointer variables, are also stored under an address in memory.
Depending on the system, pointer variables are at least large enough to store an
address, in this case 4 bytes.
In the following example we access two variables a and b with a char pointer ptr_a
and an int pointer ptr_b and output the addresses and their contents.
/* example 128 – pointers */
#include
int main(void)
{
char a='A', *ptr_a = &a;
int b=1000, *ptr_b = &b;
printf("a = %c = dec %d\n",a,a);
printf("b = %d\n",b);
printf("Address of a = %p\n",ptr_a);
printf("Value of a = %c = %d\n",*ptr_a, *ptr_a);
printf("Address of b = %p\n",ptr_b);
printf("Value of b = %d\n",*ptr_b);
printf("Address of ptr_a = %p\n",&ptr_a);
printf("Address of ptr_b = %p\n",&ptr_b);
printf("Size of ptr_a = %d\n",sizeof(ptr_a));
printf("Size of ptr_b = %d\n",sizeof(ptr_b));
}
return 0;
a = A = dec 65
b = 1000
Address of a = 0060FEFF
Value of a = A = 65
Address of b = 0060FEF4
Value of b = 1000
Address of ptr_a = 0060FEF8
Address of ptr_b = 0060FEF0
Size of ptr_a = 4
Size of ptr_b = 4
The C Programming Language by Heimo Gaicher – Chapter Pointers 10