ATMProgram.java

import java.util.Scanner;

// Class representing a Bank Account
class BankAccount {
    private double balance;

    public BankAccount(double initialBalance) {
        if (initialBalance >= 0) {
            this.balance = initialBalance;
        } else {
            System.out.println("Initial balance cannot be negative. Setting balance to 0.");
            this.balance = 0;
        }
    }

    public double getBalance() {
        return balance;
    }

    public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
            System.out.println("Successfully deposited: $" + amount);
        } else {
            System.out.println("Deposit amount must be positive.");
        }
    }

    public boolean withdraw(double amount) {
        if (amount > 0 && amount <= balance) {
            balance -= amount;
            System.out.println("Successfully withdrew: $" + amount);
            return true;
        } else if (amount > balance) {
            System.out.println("Insufficient balance for this withdrawal.");
            return false;
        } else {
            System.out.println("Withdrawal amount must be positive.");
            return false;
        }
    }
}

// Class representing the ATM
class ATM {
    private BankAccount account;
    private Scanner scanner;

    public ATM(BankAccount account) {
        this.account = account;
        this.scanner = new Scanner(System.in);
    }

    public void start() {
        System.out.println("Welcome to the ATM!");
        boolean running = true;

        while (running) {
            displayMenu();
            int choice = getUserChoice();
            switch (choice) {
                case 1:
                    handleWithdraw();
                    break;
                case 2:
                    handleDeposit();
                    break;
                case 3:
                    handleCheckBalance();
                    break;
                case 4:
                    running = false;
                    System.out.println("Thank you for using the ATM. Goodbye!");
                    break;
                default:
                    System.out.println("Invalid option. Please try again.");
            }
        }
    }

    private void displayMenu() {
        System.out.println("\n--- ATM Menu ---");
        System.out.println("1. Withdraw");
        System.out.println("2. Deposit");
        System.out.println("3. Check Balance");
        System.out.println("4. Exit");
        System.out.print("Enter your choice: ");
    }

    private int getUserChoice() {
        return scanner.nextInt();
    }

    private void handleWithdraw() {
        System.out.print("Enter amount to withdraw: ");
        double amount = scanner.nextDouble();
        account.withdraw(amount);
    }

    private void handleDeposit() {
        System.out.print("Enter amount to deposit: ");
        double amount = scanner.nextDouble();
        account.deposit(amount);
    }

    private void handleCheckBalance() {
        System.out.println("Your current balance is: $" + account.getBalance());
    }
}

// Main class to run the program
public class ATMProgram {
    public static void main(String[] args) {
        // Initialize a bank account with a sample balance
        BankAccount account = new BankAccount(1000.00);

        // Create and start the ATM
        ATM atm = new ATM(account);
        atm.start();
    }
}