error message: assignment of read-only variable

[jyo76]

Hi, I am trying to make this practice program to calculate pay for an employee.

I am using Xcode on a mac.

I get the following error messages when I try to run this...

error: assignment of read-only variable 'federalWithholding'
error: assignment of read-only variable 'stateWithholding'
error: assignment of read-only variable 'hospitalization'
error: assignment of read-only variable 'unionDues'


can anyone tell me why this is happening? heres the program so far...



#include <iostream>
#include <iomanip>
#include <string>

const double federalWithholding = 0.18;
const double stateWithholding = 0.045;
const double hospitalization = 25.65;

const double unionDues = 0.02;

using namespace std;

int main ()
{
string employeeInitials;
double hoursWorked,
hourlyRate,
totalWages,
totalDeductions,
netPay;


cout << "Enter employee initials: " << endl;
getline (cin,employeeInitials);

cout << "Enter Hours Worked" << endl;
cin >> hoursWorked;

cout << "Enter Hourly Rate" << endl;
cin >> hourlyRate;


cin >> totalWages = hoursWorked * hourlyRate;
federalWithholding = 0.18 * totalWages;
stateWithholding = 0.045 * totalWages;
hospitalization = 25.65;
unionDues = 0.02 * totalWages;
totalDeductions = federalWithholding + stateWithholding + hospitalization + unionDues;
netPay = totalWages - totalDeductions;




cout << fixed << showpoint << setprecision(2);
cout << "Employee Initials: " << employeeInitials << endl;
cout << "Hours Worked: " << hoursWorked << endl;
cout << "Total Wages: " << totalWages << endl;


cout << "\nDeductions";
cout << "Federal Withholding: " << federalWithholding << endl;
cout << "State Withholding: " << stateWithholding << endl;
cout << "Hospitalization: " << hospitalization << endl;
cout << "Union Dues: " << unionDues << endl;


cout << "\nTotal Deductions: " << totalDeductions << endl;
cout << "Net Pay: " << netPay << endl;

return 0;
}

[Moschops]

const double federalWithholding = 0.18;

federalWithholding = 0.18 * totalWages;

[firedraco]

All of the variables you are assigning to are const which means you cannot modify them.

[Moschops]

cin >> totalWages = hoursWorked * hourlyRate;

This will also cause a compile-time error.

[jyo76]

Moschops,

i think i see what ur talking about...

but its hard to tell exactly...

should i leave out

federalWithholding = 0.18 * totalWages; ??

[jyo76]

(All of the variables I am assigning to)

[jyo76]

cin >> totalWages = hoursWorked * hourlyRate;


Yeah, i caught that one! lol

so i dont need to assign value to the constants, should i just omit the lines that try to do so?

[jyo76]

thanks everybody for your input so far, Im going to go try to fix this thing!

[Moschops]

should i leave out

federalWithholding = 0.18 * totalWages; ??

Given that you seem to want to calculate the value of federalWithholding, removing the line of code that does the calculation seems a bit silly.

[jyo76]

lol, yeah just a bit Moschops...

but at least u helped me get rid of the errors...

now I just have to fix the calculations for totalDeductions...

heres the updated code...



#include <iostream>
#include <iomanip>
#include <string>

const double federalWithholding = 0.18;
const double stateWithholding = 0.045; // state withholding rate - named constant
const double hospitalization = 25.65; // hospitalization rate - named constant
const double unionDues = 0.02; // union dues rate - named constant

using namespace std;

int main ()
{
string employeeInitials; // character string storage
double hoursWorked, // decimal number input storage
hourlyRate, // decimal number input storage
totalWages,
totalDeductions,
netPay;


cout << "Enter employee initials: " << endl;
getline (cin,employeeInitials);

cout << "Enter Hours Worked" << endl;
cin >> hoursWorked;

cout << "Enter Hourly Rate" << endl;
cin >> hourlyRate;


totalWages = hoursWorked * hourlyRate;
totalDeductions = (federalWithholding + stateWithholding + hospitalization + unionDues);
netPay = totalWages - totalDeductions;




cout << fixed << showpoint << setprecision(2);
cout << "Employee Initials: " << employeeInitials << endl;
cout << "Hours Worked: " << hoursWorked << endl;
cout << "Hourly Rate: " << hourlyRate << endl;
cout << "Total Wages: " << totalWages << endl;


cout << "\nDeductions";
cout << "Federal Withholding: " << federalWithholding * totalWages << endl;
cout << "State Withholding: " << stateWithholding * totalWages << endl;
cout << "Hospitalization: " << hospitalization << endl;
cout << "Union Dues: " << unionDues * totalWages << endl;


cout << "\nTotal Deductions: " << totalDeductions << endl;
cout << "Net Pay: " << netPay << endl;

return 0;
}