C++ help: Adding Constructors & functions like variables?

I having issues displaying the final balance in this program. I'm especially having issues on adding the objects/constructors at the very end of my main.cpp file.





FILE 1: MAIN.CPP


//////////////////////////////////////鈥?br>

#include %26lt;iostream%26gt;


#include %26lt;cmath%26gt;


#include %26lt;ctime%26gt; //for time function


#include %26lt;time.h%26gt; //C time header


#include %26lt;cstdlib%26gt; //for rand() %26amp; srand() functions


#include "header.h"


using namespace std;





int main()


{


//prompt user to enter his/her name


cout %26lt;%26lt; "\nPlease enter your name: ";


char name[80]; //80 characters maximun


cin.getline(name, 80);





//prompt user to enter balance


cout %26lt;%26lt; "Enter your current balance: ";


double balance;


cin %26gt;%26gt; balance;





//prompt user to enter interest rate


cout %26lt;%26lt; "Enter the annual interest rate: ";


double annualInterestRate;


cin %26gt;%26gt; annualInterestRate;





//prompt user to enter withdraw amount


cout %26lt;%26lt; "Enter amount you want to withdraw (enter 0 if none): ";


double withdraw;


cin %26gt;%26gt; withdraw;





//prompt user to enter deposit amount


cout %26lt;%26lt; "Enter amount wou want to deposit (enter 0 if none): ";


double deposit;


cin %26gt;%26gt; withdraw;





//HERE'S MY PROBLEM:


cout %26lt;%26lt; "Your final balance is " %26lt;%26lt; amount2.getBalance(balance) + Balance::deposit(deposit) + Balance::withDraw(withdraw) %26lt;%26lt; endl;





return 0;


}











FILE 2: HEADER.H


//////////////////////////////////////鈥?br>

//create a object for the balance


//(see Exercise 9.3)


class Balance


{


private:


//the user's balance


double balance;


double amountWithdraw;


double amountDeposit;





public:


//construct a default balance object


Balance(); //prototype constructor





//construct a balance object


Balance(double newBalance); //prototype constructor





//gain access to balance, which is a private variable


double Balance::getBalance(double accessBalance);





//add the desposit to the current balance


double deposit(double accessBalance);





//subtract the withdraw from the current balance


double withDraw(double accessBalance);


}; //semicolon required!





//create a object for the annual interest rate


//(see Exercise 9.3)


class AnnualInterestRate


{


private:


double monthlyInterest; //for getInterestRate function


double withdrawAmount; //for withDraw function


double depositAmount; //for deposit function





public:


//construct a default annual interest rate object


AnnualInterestRate(); //prototype constructor





//construct a annual interest rate object


AnnualInterestRate(double newMonthlyInterest); //prototype constructor





//return the monthly interest rate


double getMonthlyInterestRate(double newMonthlyInterest); //prototype function


}; //semicolon required!





FILE 3: CONSTRUCTORS.CPP


//////////////////////////////////////鈥?br>

//(see Exercise 9.3)


Balance::Balance()


{


balance = 0;


}





//construct a balance object


//(see Exercise 9.3)


Balance::Balance(double newBalance)


{


balance = newBalance;


}





//gain access to balance, which is set to private


//(see Chp.9_header.h)


double Balance::getBalance(double accessBalance)


{


return balance;


}





//add the deposit to the balance


//(see Chp.9_header.h)


double Balance::deposit(double accessBalance)


{


return balance + accessBalance;


}





//subtract the withdraw from the balance


double Balance::withDraw(double accessBalance)


{


return balance - accessBalance;


}





//construct a default annual interest rate object


//(see Exercise 9.3)


AnnualInterestRate::AnnualInterestRate鈥?br>

{


monthlyInterest = 0;


}





//construct a annual interest rate object


//(see Exercise 9.3)


AnnualInterestRate::AnnualInterestRate鈥?newMonthlyInterest)


{


monthlyInterest = newMonthlyInterest;


}





//return the monthly interest rate


//(see Exercise 9.3)


double AnnualInterestRate::getMonthlyInterestRa鈥?newMonthlyInterest)


{


//calculate the monthly interest rate


double monthlyInterest = (newMonthlyInterest /12) * 100;





return monthlyInterest;


}|||I don't think classes work the way you think they work. Here's an example bank account class:





class BankAccount


{


private:


double balance;





public:


BankAccount(){


balance = 0;


}





BankAccount(double startBalance){


balance = startBalance;


}





double deposit(double amount){


balance += amount;


return balance;


}





double withdraw(double amount){


balance -= amount;


return balance;


}





double getBalance(){


return balance;


}


};








You would use it the following way:





double value;


cout%26lt;%26lt;"Enter a starting balance: "; cin%26gt;%26gt;value;


BankAccount myAccount(value);


cout%26lt;%26lt;"Enter a deposit amount: "; cin%26gt;%26gt;value;


myAccount.deposit(value);


cout%26lt;%26lt;"Enter a withdraw amount: "; cin%26gt;%26gt;value;


myAccount.withdraw(value);


cout%26lt;%26lt;"Final account value: "%26lt;%26lt;myAccount.getBalance()%26lt;%26lt;endl;