// ptr7.cpp 		By: Aiman Hanna -  ©1993-2006 Aiman Hanna

// This program concerns of passing parameters to functions in general.
// 
// Key Points: 	1) Are the parameters for the function below being passed by
// value, or by reference? 

#include <iostream.h>

void Twice(int x , int y)
{
// This function accepts two integers as parameters and attempt to duplicate them. 
 cout << "\n Starting \"Twice\"...." << endl; 

	cout << " x now is " << x << "\n";
	cout << " y now is " << y << "\n";

	x *= 2;
	y *= 2; 
   
 	cout << "\n x after duplication is " << x << "\n";
	cout << " y after duplication is " << y << "\n";
}



int main()
{
 int a[3];
 a[0] = 4; a[1] = 5; a[2] = 7;  

 cout << " This is the array before executing Twice \n";
 for ( int i = 0 ; i < 3 ; i++ )
	 cout << a[i] <<"\n";

 Twice(a[0], a[2]);
 
 cout << "\n\n This is the array ... after executing Twice !!!! \n";
 for ( i = 0 ; i < 3 ; i++ )
	 cout << a[i] <<"\n";

 return 0;
}
                               

// The following is the result of compilation
//Compilation successful

// The following is the result of running the program
/*
 This is the array before executing Twice
4
5
7

 Starting "Twice"....
 x now is 4
 y now is 7

 x after duplication is 8
 y after duplication is 14


 This is the array ... after executing Twice !!!!
4
5
7
*/