/* some pointer fun and games */

#include<stdio.h>

int main()
{
	int x, y;	/* integer variables */
	int *ptr;	/* a pointer to an integer variable */
	
	x = 256;	/* assigning the variable 'x' the value 256 */
	ptr = &x;	/* assigning the address of 'x' in memory to the pointer 'ptr' */

	y = *ptr;	/* ptr is dereferenced to assign the 
			   value 256 to y */
	
	printf("x is %d\n", x); 	/* printing the value of x */
	printf("&x is %u\n", &x);	/* printing the address of x */
	printf("*ptr is %d\n", *ptr);	/* printing what ptr points to */
	printf("ptr is %u\n", ptr);	/* printing the address ptr points to */
	printf("y is %d\n", y);		/* printing the value of y */

	*ptr = 37;	/* ptr is dereferenced to obtain an address in order
			   to store 37.  In other words, 'store 37 in the
			   memory location pointed to by ptr' */

	printf("x is now %d\n", x);
	printf("&x is now %u\n", &x);
	printf("*ptr is now %d\n", *ptr);
	printf("ptr is now %u\n", ptr);
	printf("y is now %d\n", y);
}