Write a Program in C++ That Passing Arguments by Value and by Reference

// Passing arguments by value and by reference.

#include <iostream>

using namespace std;

int squareByValue( int ); // function prototype (value pass)

void squareByReference( int & ); // function prototype (reference pass)

                                                   

int main()

{

   int x = 2; // value to square using squareByValue

   int z = 4; // value to square using squareByReference

   // demonstrate squareByValue

   cout << "x = " << x << " before squareByValue\n";

   cout << "Value returned by squareByValue: " 

      << squareByValue( x ) << endl;  

   cout << "x = " << x << " after squareByValue\n" << endl;

   // demonstrate squareByReference

   cout << "z = " << z << " before squareByReference" << endl;

   squareByReference( z );

   cout << "z = " << z << " after squareByReference" << endl;

} // end main

// squareByValue multiplies number by itself, stores the 

// result in number and returns the new value of number

int squareByValue( int number )

{

   return number *= number; // caller's argument not modified

} // end function squareByValue

// squareByReference multiplies numberRef by itself and stores the result

// in the variable to which numberRef refers in function main

void squareByReference( int &numberRef )

{

   numberRef *= numberRef; // caller's argument modified

} // end function squareByReference