My program is not reading from a file and inputting the data

Question

I made a program to calculate the total pay for 7 employees. The program read from a file (payroll.dat), to get data for data members "hours" and "payrate". The output for all 7 emplyeress is 0.00, datafile >> hours; datafile >> payrate; seems correct. I am not sure why why the program is not reading from the file and inputting the data into the members.

#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;

class Payroll
{
private:
    double hours;
    double payrate;
    double grosspay;

public:
    Payroll()
    {
        hours = 0.0;
        payrate = 0.0;
        grosspay = 0.0;

    }

    Payroll(double h, double p)
    {
        hours = h;
        payrate = p;
        grosspay = hours * payrate;
    }

    double setHours(double h)
    {
        hours = h;
    }

    double setPayrate(double p)
    {
        payrate = p;
    }

    double getHours()
    {
        return hours;
    }

    double getPayrate()
    {
        return payrate;
    }

    double getGrosspay()
    {
        return grosspay;
    }

};

const int employees = 7;

int main()
{
    double hours;
    double payrate;
    double grosspay;


    int index;

    Payroll totalPay[employees];
    {
        ifstream datafile;

        datafile.open("payroll.dat");

        if (!datafile)
            cout << "Error opening data file \n";

        else
        {
            for (index = 0; index < 7; index++)  
            {
                datafile >> hours;
                datafile >> payrate;
                grosspay = hours * payrate;

                
                cout << endl;
                cout << fixed << setprecision(2);
                cout << "Employee" << (index + 1) << ": " << totalPay[employees].getGrosspay() << endl;
            }
        }

        datafile.close();
    }

    return 0;
} 

Answer 1

In your innermost for loop, you are doing:

grosspay = hours * payrate;

but the variable grosspay is just a local variable, and does not update the totalPay array. So this line:

cout << "Employee" << (index + 1) << ": " << totalPay[employees].getGrosspay() << endl;

prints the grosspay of a default constructed Payroll.

Instead of assigning to a local variable, you need to do something like:

totalPay[index] = Payroll(hours, payrate);

which constructs a correct Payroll object and assigns it to an index in the array.