Java Polymorphism: BankAccount base class with Savings, Checking Account subclasses

// BankAccount.java
// Define a class named BankAccount
class BankAccount {
  
  // Declare a private double variable balance
  private double balance;

  // Define a constructor that takes a double initialBalance as a parameter
  public BankAccount(double initialBalance) {
    // Assign the parameter initialBalance to the instance variable balance
    this.balance = initialBalance;
  }

  // Define a method to get the current balance
  public double getBalance() {
    // Return the current balance
    return balance;
  }

  // Define a method to deposit an amount to the balance
  public void deposit(double amount) {
    // Add the amount to the current balance
    balance += amount;
  }

  // Define a method to withdraw an amount from the balance
  public void withdraw(double amount) {
    // Check if the amount to be withdrawn is less than or equal to the current balance
    if (amount <= balance) {
      // Subtract the amount from the current balance
      balance -= amount;
    } else {
      // Print "Insufficient funds." to the console if the balance is insufficient
      System.out.println("Insufficient funds.");
    }
  }
} 

// SavingsAccount.java
// Define a class named SavingsAccount that extends BankAccount
class SavingsAccount extends BankAccount {
  
  // Declare a private double variable withdrawalLimit
  private double withdrawalLimit;

  // Define a constructor that takes a double initialBalance and a double withdrawalLimit as parameters
  public SavingsAccount(double initialBalance, double withdrawalLimit) {
    // Call the constructor of the superclass BankAccount with initialBalance
    super(initialBalance);
    // Assign the parameter withdrawalLimit to the instance variable withdrawalLimit
    this.withdrawalLimit = withdrawalLimit;
  }

  // Override the withdraw method from the BankAccount class
  @Override
  public void withdraw(double amount) {
    // Check if the amount to be withdrawn is less than or equal to the withdrawal limit
    if (amount <= withdrawalLimit) {
      // Call the withdraw method of the superclass BankAccount with amount
      super.withdraw(amount);
    } else {
      // Print "Withdrawal limit exceeded." to the console if the amount exceeds the withdrawal limit
      System.out.println("Withdrawal limit exceeded.");
    }
  }
} 

// CheckingAccount.java
// Define a class named CheckingAccount that extends BankAccount
class CheckingAccount extends BankAccount {
  
  // Declare a private double variable overdraftFee
  private double overdraftFee;

  // Define a constructor that takes a double initialBalance and a double overdraftFee as parameters
  public CheckingAccount(double initialBalance, double overdraftFee) {
    // Call the constructor of the superclass BankAccount with initialBalance
    super(initialBalance);
    // Assign the parameter overdraftFee to the instance variable overdraftFee
    this.overdraftFee = overdraftFee;
  }

  // Override the withdraw method from the BankAccount class
  @Override
  public void withdraw(double amount) {
    // Check if the amount to be withdrawn is less than or equal to the current balance
    if (amount <= getBalance()) {
      // Call the withdraw method of the superclass BankAccount with amount
      super.withdraw(amount);
    } else {
      // Print "Overdraft fee applied." to the console if the amount exceeds the current balance
      System.out.println("Overdraft fee applied.");
      // Call the withdraw method of the superclass BankAccount with the amount plus the overdraft fee
      super.withdraw(amount + overdraftFee);
    }
  }
} 

// Main.java
// Main class definition
public class Main {
  // Main method, program entry point
  public static void main(String[] args) {
    // Create a SavingsAccount object with a balance of 2000 and a limit of 650
    BankAccount savingsAccount = new SavingsAccount(2000, 650);
    // Create a CheckingAccount object with a balance of 1000 and a limit of 100
    BankAccount checkingAccount = new CheckingAccount(1000, 100);

    // Withdraw 300 from the savings account
    withdrawFromAccount(savingsAccount, 300);
    // Withdraw 250 from the checking account
    withdrawFromAccount(checkingAccount, 250);

    // Print the current balance of the savings account
    System.out.println("Savings Account Balance: " + savingsAccount.getBalance());
    // Print the current balance of the checking account
    System.out.println("Checking Account Balance: " + checkingAccount.getBalance());
  }

  // Method to withdraw a specified amount from a given bank account
  public static void withdrawFromAccount(BankAccount account, double amount) {
    // Call the withdraw method on the account with the specified amount
    account.withdraw(amount);
  }
}