Communication between Functions

Assignment 6 - Void Functions vs Value-returning Functions

Another way that the called function can communicate a result back to the calling function is through the function value. In this exercise, you will start with a void function and convert it to a value-returning function.

Here is a payroll program.

//*****************************************************
// Program 6: Payroll Program
// Programmer: Your Name
// Completed : date
// Status    : Complete
//
// This program calculates and prints your weekly pay.
//*****************************************************

#include <iostream.h>
#include <iomanip.h>

void CalcPay(float hoursWorked, float payRate, float& pay);

int main()
{
   float hoursWorked;  // hours worked in a week
   float payRate;      // hourly pay rate in dollars
   float pay;          // weekly pay in dollars

// Set up floating point output format
   cout << setiosflags(ios::fixed) << setprecision(2);

// Set the number of hours worked and hourly pay rate
   hoursWorked = 35.0;
   payRate     = 10.5;

// Calculate the weekly pay
   CalcPay(hoursWorked, payRate, pay);

// Print hours worked, pay rate, and your weekly pay
   cout << "Your weekly pay information" << endl;
   cout << "   Hours worked: "
        << setw(8) << hoursWorked << endl;
   cout << "   Pay rate    : "
        << setw(8) << payRate << endl;
   cout << "   Weekly pay  : "
        << setw(8) << pay << endl << endl;
   return 0;
}

//**********************************************************
// Function CalcPay()
//
// Purpose - this function calculates your weekly pay and
//    returns it to the calling function in parameter pay.
//**********************************************************

void CalcPay( float hoursWorked,  // hours worked in a week
              float payRate,      // hourly pay rate in dollars
              float& pay)         // weekly pay in dollars
{
// Calculate the weekly pay
   pay = hoursWorked * payRate;
}

Exercise Steps:

1. Make a copy of the program above and run it.
2. Change the CalcPay() function to a value-returning function. The call to CalcPay() might look something like this:

      pay = CalcPay(hoursWorked, payRate); 

   Your new program should still produce the same output as before.

3. Run your new program and verify that it produces the same output as the original program.

Exercise Deliverables:

1. The source code listing of you program using a value-returning function.