//******************************************************
// Filename:    Demo_Pointer_Passing.cpp
// Purpose:     Demonstrate Passing a Pointer
// Comments:    Passing by reference is shown first with 
//              passing a pointer shown second.
// Author:      Ken Busbee; © 2009 Kenneth Leroy Busbee
// Date:        Apr 15, 2009
// Licensed by: Kenneth Leroy Busbee under a 
//              Creative Commons Attribution License (CC-BY 3.0)
//              http://creativecommons.org/licenses/by/3.0/
//******************************************************

// Headers and Other Technical Items

#include <iostream>
using namespace std;

// Function Prototypes

void pass_by_reference(int &thing1, char &thing2, double &thing3);
void pass_a_pointer(int * item1, char *item2, double *item3);
void pause(void);

// Variables

int     age   = 26;
char    grade = 'B';
double  money = 2.34;

int *    ptr_to_age   = &age;
char *   ptr_to_grade = &grade;
double * ptr_to_money = &money;

//******************************************************
// main
//******************************************************

int main(void)
  {
  cout << "\nThe integer age ------->: " << age;
  cout << "\nThe character grade --->: " << grade;
  cout << "\nThe double money ------>: " << money;
  
  pass_by_reference(age, grade, money);

  cout << "\nThe integer age ------->: " << age;
  cout << "\nThe character grade --->: " << grade;
  cout << "\nThe double money ------>: " << money;

  pause();
  pass_a_pointer(ptr_to_age, ptr_to_grade, ptr_to_money);

  cout << "\nThe integer age ------->: " << age;
  cout << "\nThe character grade --->: " << grade;
  cout << "\nThe double money ------>: " << money;

  pause();
  return 0;
  }

//******************************************************
// pass_by_reference
//******************************************************

void pass_by_reference(int &thing1, char &thing2, double &thing3)
  {
  cout << "\n\n**** The function starts - pass by reference. ****\n";
  cout << "\nEnter the new age ----->: ";
  cin >> thing1;
  cout << "\nEnter the new grade --->: ";
  cin >> thing2;
  cout << "\nEnter the new money --->: ";
  cin >> thing3;
  cout << "\n**** The function ends. ****\n";
  return;
  }

//******************************************************
// passing_a_pointer
//******************************************************

void pass_a_pointer(int * item1, char *item2, double *item3)
  {
  cout << "\n\n**** The function starts - pass a pointer. ****\n";
  cout << "\nEnter the new age ----->: ";
  cin >> *item1;
  cout << "\nEnter the new grade --->: ";
  cin >> *item2;
  cout << "\nEnter the new money --->: ";
  cin >> *item3;
  cout << "\n**** The function ends. ****\n";
  return;
  }

//******************************************************
// pause
//******************************************************

void pause(void)
  {
  cout << "\n\n";
  system("PAUSE");
  cout << "\n\n";
  return;
  }

//******************************************************
// End of Program
//******************************************************