COSC 1320 - C++ Programming and
ITSE 1307 - Introduction to C++ Programming
Bob Comer, Professor of Computer Studies

Example Program - Mileage.cpp

```//******************************************************************
// Mileage program
// Programmer: Bob Comer
// Completed : 1/25/2006
// Status    : Complete
//
// This program computes your mileage for a trip given number of
// gallons of gas used, and starting and ending mileage
//******************************************************************

#include <iostream>      // input/output declarations
#include <iomanip>       // i/o manupulator declarations
using namespace std;

// function prototypes
float mileage( float startMiles, float endMiles, float gallonsUsed );

int main()
{
float startMiles;      // Starting mileage
float endMiles;        // Ending mileage
float gallonsUsed;     // Gallons of gas used
float mpg;             // Computed miles per gallon

//  Set up floating point output format
cout << fixed << showpoint << setprecision(2);

//  Get starting and ending mileage, and gallons of gas used
cout << "Enter starting mileage: ";
cin  >> startMiles;
cout << "Enter ending mileage: ";
cin  >> endMiles;
cout << "Enter number of gallons of gas used: ";
cin  >> gallonsUsed;

//  Calculate mileage
mpg = mileage( startMiles, endMiles, gallonsUsed );

//  Print starting and ending mileage, gallons of gas used,
//  and calculated mileage
cout << "For a trip with:" << endl;
cout << "    " << gallonsUsed << " gallons of gas used" << endl;
cout << "    and a starting mileage of " << startMiles << endl;
cout << "    and  an ending mileage of " << endMiles << endl;
cout << "    the mileage per gallon is " << mpg << endl;

return 0;
}

// Function mileage
//
// Purpose: calculates and returns the trip mileage

float mileage( float startMiles,     // In - starting mileage
float endMiles,       // In - ending mileage
float gallonsUsed )   // In - gallons of gas used
{
float milesTraveled;   // Total miles traveled
float mpg;             // Computed miles per gallon

//  Calculate mileage
milesTraveled = endMiles - startMiles;
mpg = milesTraveled / gallonsUsed;

return mpg;
}
```