Call by reference ( Example )

void swap(int *x, int *y)

{
  int temp;
  temp = *x;
  *x = *y;
  *y = temp;
  printf("Swapped values are a = %d and b = %d", *x, *y);
}
void main()
{
  int a = 7, b = 4;
  swap(&a, &b);
  printf("Original values are a = %d and b = %d",a,b);
  printf("The values after swap are a = %d and b = %d",a,b);
}  

Output:
  Original Values are a = 7 and b = 4
  Swapped values are a = 4 and b = 7