Undeclared identifier help, can't figure out what's wrong

[Toothless LL]

It pops up and shows these messages when compiling, but I couldn't figure out what's wrong, can anyone help me? I just want to write a program where user types in the gross pay and it calculates the amount and outputs that.
It shows these errors:

(26): error C2146: syntax error : missing ';' before identifier 'endl'
(26): warning C4551: function call missing argument list
(27): error C2065: 'amount' : undeclared identifier
(28): error C2065: 'NetPay' : undeclared identifier
(28): error C2065: 'amount' : undeclared identifier
(28): error C2065: 'amount' : undeclared identifier
(28): error C2065: 'federalTax' : undeclared identifier
(28): error C2065: 'amount' : undeclared identifier
(28): error C2065: 'stateTax' : undeclared identifier
(28): error C2065: 'amount' : undeclared identifier
(28): error C2065: 'socialSecurityAndMedicareTax' : undeclared identifier
(28): error C2065: 'healthInsurance' : undeclared identifier
(29): error C2065: 'NetPay' : undeclared identifier

  // Paycheck project
#include <iostream>
#include <iomanip> 
#include <string>
using namespace std;

int main()
{ 
	string firstName,
		lastName,
		month,
		year,
	double amount,
	const double federalTax = .15,
		stateTax = .035,
		socialSecurityAndMedicareTax = .085,
		healthInsurance = 75;
	cout << "Please enter your first name." << endl;
	cin >> firstName >> endl;
	cout << "Please enter your last name." << endl;
	cin >> lastName >> endl;
	cout << "Please eneter the month of your paycheck." << endl;
	cin >> month >> endl;
	cout << "Please enter the year of your paycheck." << endl;
	cin >> year >> endl;
	cout << "Please enter the gross pay of your paycheck." endl;
	cin >> amount >> endl;
	NetPay = amount-(amount*federalTax)-(amount*stateTax)-(amount*socialSecurityAndMedicareTax)-(healthInsurance);
	cout << setprecision(2) << fixed << NetPay << endl;
		
	return 0;
}

Thanks for help in advance!

[E0p9LyTq]

Always declare variables on separate lines. cin and endl don't work together, endl is only used with cout. You didn't declare what type NetPay is.

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

int main()
{
   string firstName;
   string lastName;
   string month;
   string  year;
   double amount;
   const double federalTax = .15;
   const double stateTax = .035;
   const double socialSecurityAndMedicareTax = .085;
   const double healthInsurance = 75;
   
   cout << "Please enter your first name." << endl;
   cin >> firstName;

   cout << "Please enter your last name." << endl;
   cin >> lastName;

   cout << "Please eneter the month of your paycheck." << endl;
   cin >> month;

   cout << "Please enter the year of your paycheck." << endl;
   cin >> year;

   cout << "Please enter the gross pay of your paycheck." << endl;
   cin >> amount;

   double NetPay = amount-(amount*federalTax)-(amount*stateTax)-amount*socialSecurityAndMedicareTax)-(healthInsurance);
   cout << setprecision(2) << fixed << NetPay << endl;

   return 0;
}

[Toothless LL]

Thanks Furry Guy! That solved my problem! Also, can you explain what does const do? I can't seem to find an answer in the terms that I understand. All I know was that if I use const, the users can't change the numbers or something? Thanks again!

[Zhuge]

It declares the variable as constant. After you set those values, they can't be changed. It is useful as a safety measure to prevent an accident like changing the healthInsurance value at some point and resulting in inconsistent results throughout your program.