GasMileage And SalesCommisCal

//GasMileage Header and CPP files
#include <string>
#pragma once

class GasMileage
{
private:
    //holds total for miles
    double milestotal;
    //holds total for gallons
    double gallonstotal;

public:
    explicit GasMileage(std::string);
    explicit GasMileage(std::string, double, double);
    void CalculateMileage();

    double GetMilesTraveledTotal();
    double GetGallonsUsedTotal();

    void IncMilesTraveledTotal(double);
    void IncGallonsUsedTotal(double);

};

#include "stdafx.h"
#include "GasMileage.h"
#include <iostream>
#include <iomanip>

GasMileage::GasMileage(std::string tripname)
{
    gallonstotal = 0;
    milestotal = 0;
    //mpgtotal = 0;
    std::cout << tripname << std::endl;
}
GasMileage::GasMileage(std::string tripname, double miles, double gallon)
{
    gallonstotal = gallon;
    milestotal = miles;
    //mpgtotal = mpg;
    std::cout << tripname << std::endl;
}

double GasMileage::GetMilesTraveledTotal()
{
    return milestotal;
}
double GasMileage::GetGallonsUsedTotal()
{
    return gallonstotal;
}
void GasMileage::IncMilesTraveledTotal(double miles)
{
    milestotal += miles;
}
void GasMileage::IncGallonsUsedTotal(double gallons)
{
    gallonstotal += gallons;
}
void GasMileage::CalculateMileage()
{
    double milesdriven = 0;
    double gallonsused = 0;
    do
    {

        std::cout << "Enter miles driven (-1 or less to quit): ";
        std::cin >> milesdriven;
        if (milesdriven >= 0)
        {
            IncMilesTraveledTotal(milesdriven);
            std::cout << "Enter gallons used: ";
            std::cin >> gallonsused;
            IncGallonsUsedTotal(gallonsused);
            double mpgthistrip = milesdriven / gallonsused;
            std::cout << std::setprecision(6) << std::fixed;
            std::cout << "MPG this trip: " << mpgthistrip << std::endl;

            std::cout << "Total MPG: " << (GetMilesTraveledTotal() / GetGallonsUsedTotal()) << std::endl;
            std::cout << std::endl;
        }

    } while (milesdriven >= 0);
}

// Sales Commission Calculator Header and CPP
#pragma once
class SalesCommissionCalculator
{
public:
    explicit SalesCommissionCalculator();
    virtual ~SalesCommissionCalculator();
    void SalesPersonCalculations();
};

#include "stdafx.h"
#include "SalesCommissionCalculator.h"
#include <iostream>
#include <iomanip>

SalesCommissionCalculator::SalesCommissionCalculator()
{
}


SalesCommissionCalculator::~SalesCommissionCalculator()
{
}

void SalesCommissionCalculator::SalesPersonCalculations()
{
    double dollars = 0;
    double salary = 0;

    do
    {
        std::cout << "Enter sales in dollars (-1 or less to quit): ";
        std::cin >> dollars;
        //std::cout << std::endl;
        if (dollars >= 0)
        {
            salary = 200 + (dollars * 0.09);
            std::cout << std::setprecision(2) << std::fixed;
            std::cout << "Salary is: " << salary;
        }
        std::cout << std::endl;
    } while (dollars >= 0);
}