#include <iostream> 
using namespace std; 
 
void f(int *j);
 
int main() 
{ 
  int i; 
  int *p; 
 
  p = &i; 
 
  f(p);   // pass a pointer 
 
  cout << i;
 
  return 0; 
} 
 
void f(int *j) 
{ 
  *j = 100; 
}
