/* File: swap3.c

   What happens if you forget the &?
*/

#include <stdio.h>

void swap(int *ptr1, int *ptr2) ;


int main() {
   int a, b ;

   a = 79 ;
   b = 42 ;
   printf("a = %d, b = %d\n", a, b) ;

   swap(a, b) ;
   printf("a = %d, b = %d\n", a, b) ;

   return 0 ;
}


/* function: swap(a,b)

   exchanges the values stored in a & b.
*/

void swap(int *ptr1, int *ptr2) {
   int temp;

   printf("ptr1 = %p, *ptr1 = %d\n", ptr1, *ptr1) ;
   printf("ptr2 = %p, *ptr2 = %d\n", ptr2, *ptr2) ;

   temp = *ptr1 ;
   *ptr1 = *ptr2 ;
   *ptr2 = temp ;

   return ;
}