Recap - Bank Account Manager

Part of the Object Oriented Programming section of Coddy's C++ journey. Lesson 33 of 104.

Challenge

Easy

Let's build a complete Bank Account Manager that brings together all the class property concepts you've learned in this chapter: private members with getters and setters, const member functions, mutable members, static variables and methods, and friend functions.

You'll create two files to organize your code:

BankAccount.h: Define a BankAccount class that manages account data with proper encapsulation. Your class should have:
- Private members: accountNumber (string), ownerName (string), balance (double), and a mutable int queryCount to track how many times the balance has been checked
- A private static member totalAccounts to track how many accounts exist
- A constructor that takes the account number, owner name, and initial balance. It should initialize queryCount to 0 and increment totalAccounts
- Const getters: getAccountNumber(), getOwnerName(), and getBalance(): the balance getter should increment queryCount each time it's called
- A const getter getQueryCount() that returns how many times the balance was checked
- A deposit(double amount) method that adds to the balance only if the amount is positive
- A withdraw(double amount) method that subtracts from the balance only if the amount is positive and doesn't exceed the current balance
- A static method getTotalAccounts() that returns the total number of accounts created
- Declare a friend function transfer(BankAccount& from, BankAccount& to, double amount) that moves money between accounts. It should only transfer if the amount is positive and the source has sufficient funds
Define the static member and the friend function after the class definition.
main.cpp: Demonstrate all these features working together. Read two owner names and two initial balances from input (four lines total: name1, balance1, name2, balance2), then:
- Create two BankAccount objects with account numbers "ACC001" and "ACC002"
- Print "Total accounts: <count>"
- Print "<name>: $<balance>" for the first account
- Print "<name>: $<balance>" for the second account
- Deposit 500.0 into the first account
- Print "After deposit - <name>: $<balance>" for the first account
- Transfer 300.0 from the first account to the second using the friend function
- Print "After transfer:"
- Print " <name>: $<balance>" for the first account
- Print " <name>: $<balance>" for the second account
- Print "Query count for <name>: <count>" for the first account

Format all balance values with two decimal places using std::fixed and std::setprecision(2) from <iomanip>. Convert balance inputs from strings to doubles using std::stod().

Don't forget header guards in your header file and to include <string> and <iostream> where needed.

Try it yourself

#include <iostream>
#include <string>
#include <iomanip>
#include "BankAccount.h"

int main() {
    // Read input
    std::string name1, name2;
    std::string balance1Str, balance2Str;
    
    std::getline(std::cin, name1);
    std::getline(std::cin, balance1Str);
    std::getline(std::cin, name2);
    std::getline(std::cin, balance2Str);
    
    double balance1 = std::stod(balance1Str);
    double balance2 = std::stod(balance2Str);
    
    // Set output formatting for 2 decimal places
    std::cout << std::fixed << std::setprecision(2);
    
    // TODO: Create two BankAccount objects with account numbers "ACC001" and "ACC002"
    
    // TODO: Print "Total accounts: <count>"
    
    // TODO: Print "<name>: $<balance>" for the first account
    
    // TODO: Print "<name>: $<balance>" for the second account
    
    // TODO: Deposit 500.0 into the first account
    
    // TODO: Print "After deposit - <name>: $<balance>" for the first account
    
    // TODO: Transfer 300.0 from the first account to the second using the friend function
    
    // TODO: Print "After transfer:"
    
    // TODO: Print "  <name>: $<balance>" for the first account (note the 2-space indent)
    
    // TODO: Print "  <name>: $<balance>" for the second account (note the 2-space indent)
    
    // TODO: Print "Query count for <name>: <count>" for the first account
    
    return 0;
}