// pass by value, reference, and pointer
#include <iostream.h>

void swap0(int first, int second) // caution: this function does not work!
{
   int temp = first;
   first = second;
   second = temp;
}

void swap(int& first, int& second)
{
   int temp = first;
   first = second;
   second = temp;
}

void swap(int* first, int* second)
{
   int temp = *first;
   *first = *second;
   *second = temp;
}

void main()
{
      int i = 7;
      int j = 8;
      swap0(i,j);
      cout << i << j << endl;
      swap(i,j);
      cout << i << j << endl;
      swap(&i,&j);
      cout << i << j << endl;
}