/*File:  Functions04.cpp

This C++ program illustrates functions with value
parameters, reference parameters, and no return 
value

This program displays the following text on the 
screen:

In main
a = 10 b = 20.1
In aFunction
x = 10 y = 20.1
Change x and y
Still in aFunction
x = 100 y = 200.1
Back in main
a = 100 b = 20.1

************************************************/

#include <iostream>
using namespace std;

//Note that the first parameter is a reference
// parameter.
void aFunction(int &x,double y){
  cout << "In aFunction" << endl;
  cout << "x = " << x << " y = " << y << endl;
  cout << "Change x and y" << endl;
  x = 100;
  y = 200.1;
  cout << "Still in aFunction" << endl;
  cout << "x = " << x << " y = " << y << endl;
}//end aFunction
//---------------------------------------------//

int main(){//Global main function.
  cout << "In main" << endl;
  int a = 10;
  double b = 20.1;
  cout << "a = " << a << " b = " << b << endl;
  aFunction(a,b);
  cout << "Back in main" << endl;
  cout << "a = " << a << " b = " << b << endl;
  return 0;
}//end main function

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