Novice having problem with payroll program

[archer86]

The following program is part of an assignment using a base class and derived classes to calculate payroll.

When I compile I get the message:
[Linker error] undefined reference to `vtable for payroll'
C:\DOCUME~1\will\LOCALS~1\Temp\ccCmbaaa.o(.text+0x388) In function `ZN7payrollD1Ev':
[Linker error] undefined reference to `vtable for payroll'
C:\DOCUME~1\will\LOCALS~1\Temp\ccCmbaaa.o(.text+0x388) ld returned 1 exit status

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

class payroll {
ifstream fin;
public: char employeename[14], maritalstatus;
        int employeeid, n;
        float taxrate;
        double hoursworked, overtimehours, regularhours;
        double hourlyrate, regularpay, totalnetpay, annualpay;
        double taxamount, avgnetpay, netpay, grosspay, overtimepay;
        virtual void findgrosspay();
        void findtaxamount();
        void findnetpay();
        void printheaders();
        void printdata();
        void printavgnet();
        payroll();
        ~payroll();
        void printreport(); };

class salaried : public payroll {
public: void findgrosspay() {
             overtimehours = 0;
             regularpay = 0;
             overtimepay = 0;
             grosspay = 0;
             if (hoursworked > 0) {
                 overtimepay = hoursworked * (regularpay / 52 / 40);
                 regularpay = hourlyrate / 52;
             }//If
             grosspay = regularpay + overtimepay;
} };

class hourly : public payroll {
public: void findgrosspay() {
             overtimehours = 0;
             regularpay = 0;
             overtimepay = 0;
             grosspay = 0;
             if (hoursworked > 40 ) {
                 overtimehours = hoursworked - 40;
                 regularpay = hoursworked * hourlyrate;
                 overtimepay = overtimehours * (hourlyrate * 1.5);
                 grosspay = regularpay + overtimepay; }
             else
                 grosspay = hoursworked * hourlyrate;
                 regularpay = grosspay; 
} };

payroll::payroll() {
fin.open("payroll.dat"); }
payroll::~payroll() {
fin.close();  }

//void payroll::findgrosspay() {
//     overtimehours = 0;
//     regularpay = 0;
//     overtimepay = 0;
//     grosspay = 0;
//     if (hoursworked > 40 ) {
//        overtimehours = hoursworked - 40;
//        regularpay = hoursworked * hourlyrate;
//        overtimepay = overtimehours * (hourlyrate * 1.5);
//        grosspay = regularpay + overtimepay; }
//     else
//        grosspay = hoursworked * hourlyrate;
//        regularpay = grosspay; 
//}// findgrosspay

void payroll::findtaxamount() {
     taxrate = .30;
     taxamount = grosspay * taxrate;
}// findtaxamount

void payroll::findnetpay()  {
     netpay = grosspay - taxamount;
     totalnetpay = totalnetpay + netpay;
}// findnetpay

void payroll::printavgnet() {
     avgnetpay = totalnetpay / n;
     cout<<endl<<"The average net pay for "<<n <<" employees is "
     <<setw(8)<<setprecision(2)<<fixed<<left<<showpoint<<avgnetpay<<endl;
}// printavgnet
     
void payroll::printheaders()  {
     cout<<setw(45)<<"-PAYROLL REPORT-"<<endl<<endl;
	 cout<<" NAME      ID   HW   OT    RT-PAY  OT-PAY   GROSS"
		   "    TAX   NETPAY"<<endl;
cout<<"-----------------------------------------------------------------"<<endl; 
}//printheaders

void payroll::printdata()    {
 	 cout<<setw(10)<<left<<employeename<<setw(4)<<employeeid;
     cout<<setprecision(2)<<setiosflags(ios::fixed | ios::showpoint);
 	 cout<<setw(6)<<right<<hoursworked<<setw(5)<<overtimehours<<setw(8)
     <<regularpay<<setw(8)<<overtimepay<<setw(8)<<grosspay<<setw(8)
     <<taxamount<<setw(8)<<netpay<<endl;  
}//printdata

void payroll::printreport()    {
     n = 0;
     printheaders();
     while (fin>>employeename>>employeeid>>maritalstatus>>hoursworked>>hourlyrate) {
           if (employeeid < 9000) 
               hourly findgrosspay();
           else
               salaried findgrosspay();
           findtaxamount();
           findnetpay();
           printdata();
           n++;
     }// While
     printavgnet();
}// printreport

int main() {
    payroll employee;
    employee.printreport();
} //main 

I was progressing nicely until now. Can someone point me in the right direction?

Many thanks.

[dboyce]

Hello,

I compile the code using VStudio 2005 and get an error on the line

hourly findgrosspay();

I assume you're trying to call the findgrosspay method on the hourly class. You have to instantiate the class as an object before invoking the function.

[archer86]

Isn't that what I did here:

class hourly : public payroll {
public: void findgrosspay() {
overtimehours = 0;
regularpay = 0;
overtimepay = 0;
grosspay = 0;
if (hoursworked > 40 ) {
overtimehours = hoursworked - 40;
regularpay = hoursworked * hourlyrate;
overtimepay = overtimehours * (hourlyrate * 1.5);
grosspay = regularpay + overtimepay; }
else
grosspay = hoursworked * hourlyrate;
regularpay = grosspay;
} };

findgrosspay() is declared a virtual function in the base class and defined in the subclasses hourly and salaried.

[dboyce]

There are two issues

1) hourly findgrosspay(); is not the correct syntax for calling a member function on a class. If you want to call hourly memberfunction you have to be explicit hourly::findgrosspay(); by using the ::

2) You need to uncomment the void payroll::findgrosspay() function definition otherwise you'll get unresolved external for the findgrosspay on the payroll class. The reason is because you defined the function as virtual which means there has to be a definition on the payroll class. If you don't want to implement on the payroll class and force inherited class to implent than use pure virtual by replacing
virtual void findgrosspay();
with
virtual void findgrosspay() = 0;

[archer86]

Got it to compile without errors.

Thanks for your help.

[tdigdug]

Are you in my same class with SUNY

[archer86]

Is it ESC? If so, quite so.

[archer86]

I've been pointed in the right direction. I will set out to restructure the code. I've received a very good sample of what it should look like. This is how we learn.

Thanks all!

[tdigdug]

This is for week 4 right. I am surprised how many lines. I am bearly using 49 lines. And yes ESC here as well.