Project 3: Bank Account System | Advanced C++

Advanced C++ — Project 3: Bank Account System

Build a Bank Account System

Time to put your OOP knowledge to the test! You'll build two classes that model a real banking system — a base Account class and a SavingsAccount class that extends it.

YOUR TASK

Part A — Account class

Private members: string owner, double balance, vector<string> history
Constructor: Account(string owner, double initialBalance)
void deposit(double amount) — adds to balance, records "Deposit: X" in history
void withdraw(double amount) — subtracts from balance only if funds are sufficient, records "Withdrawal: X"; otherwise prints "Insufficient funds"
void printStatement() const — prints owner, balance, then every history entry

Part B — SavingsAccount class (inherits Account)

Additional private member: double interestRate
Constructor: SavingsAccount(string owner, double balance, double rate)
void applyInterest() — deposits balance * interestRate (call deposit() with that amount)

In main, run exactly this sequence:

Create Account acc("Alice", 1000)
acc.deposit(500)
acc.withdraw(200)
acc.withdraw(2000) — should print Insufficient funds
acc.printStatement()
Create SavingsAccount sav("Bob", 2000, 0.05)
sav.applyInterest()
sav.printStatement()

Hint 1 — Account class structure

class Account {
protected:
  string owner;
  double balance;
  vector<string> history;
public:
  Account(string o, double b) : owner(o), balance(b) {}
  void deposit(double amount) {
    balance += amount;
    history.push_back("Deposit: " + to_string((int)amount));
  }
  void withdraw(double amount) {
    if (amount > balance) { cout << "Insufficient funds" << endl; return; }
    balance -= amount;
    history.push_back("Withdrawal: " + to_string((int)amount));
  }
  void printStatement() const { ... }
};

Hint 2 — SavingsAccount & inheritance

Use protected (not private) on Account members so SavingsAccount can access balance directly for the interest calculation.

class SavingsAccount : public Account {
private:
  double interestRate;
public:
  SavingsAccount(string o, double b, double r)
    : Account(o, b), interestRate(r) {}
  void applyInterest() {
    deposit(balance * interestRate);
  }
};

Hint 3 — printStatement format

void printStatement() const {
  cout << "Owner: " << owner << endl;
  cout << "Balance: " << balance << endl;
  cout << "--- Transactions ---" << endl;
  for (const string& t : history)
    cout << t << endl;
}

Note: to_string((int)amount) converts the deposit/withdrawal amount to a whole-number string to keep the output clean.

Expected Output:

Insufficient funds
Owner: Alice
Balance: 1300
--- Transactions ---
Deposit: 500
Withdrawal: 200
Owner: Bob
Balance: 2100
--- Transactions ---
Deposit: 100

Language:

Input:

Code Editor Ready

Output

Console

Console initialized...
Ready for Project 3: Bank Account System

> Build your solution and hit "Check My Code"
> Once it passes, the Complete button will activate!