javalab10.java

import java.util.Scanner;

class Bank 
{
    private static int accNo = 1001; 
    private String address, name;
    private double balance;
    private int accountNum;

    Bank(String address, String name, double balance) 
    {
        this.address = address;
        this.name = name;
        this.balance = balance;
        this.accountNum = accNo++; // Assign current accNo, then increment
    }

    // Deposit method
    void deposit(double amt) 
    {
        if (amt < 0) 
        {
            System.out.println("Amount can't be negative!!");
        } 
        else 
        {
            balance += amt;
            System.out.println("Amount deposited successfully!");
        }
    }

    // Withdraw method
    void withdraw(double amt) 
    {
        if (amt < 0) 
        {
            System.out.println("You can't withdraw a negative amount!");
        } 
        else if (amt > balance) 
        {
            System.out.println("You can't withdraw more than the balance amount!!");
        } 
        else 
        {
            balance -= amt;
            System.out.println("Withdrawal successful!");
        }
    }

    // Change address
    void changeAddress(String newAddress) 
    {
        this.address = newAddress;
        System.out.println("Address updated successfully!");
    }

    // Display account details
    void show() 
    {
        System.out.println("\nAccount Number: " + accountNum);
        System.out.println("Name: " + name);
        System.out.println("Address: " + address);
        System.out.println("Balance: $" + balance);
    }

    // Get account number
    int getAccountNum() 
    {
        return accountNum;
    }
}

public class javalab10 
{
    public static void main(String[] args) 
    {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter number of bank accounts: ");
        int n = sc.nextInt();
        Bank[] accounts = new Bank[n];

        // Create accounts
        for (int i = 0; i < n; i++) 
        {
            sc.nextLine();
            System.out.println("\nAccount " + (i + 1));
            System.out.print("Name: ");
            String name = sc.nextLine();
            System.out.print("Address: ");
            String address = sc.nextLine();
            System.out.print("Initial Balance: ");
            double balance = sc.nextDouble();
            accounts[i] = new Bank(address, name, balance);
        }

        int choice;
        do 
        {
            System.out.println("\nMenu:");
            System.out.println("1. Deposit");
            System.out.println("2. Withdraw");
            System.out.println("3. Change Address");
            System.out.println("4. Show All Accounts");
            System.out.println("5. Exit");
            System.out.print("Enter your choice: ");
            choice = sc.nextInt();

            switch (choice) 
            {
                case 1: // Deposit
                    System.out.print("Enter Account Number: ");
                    int accNum = sc.nextInt();
                    Bank account = findAccount(accounts, accNum);
                    if (account != null) 
                    {
                        System.out.print("Enter amount to deposit: ");
                        double amt = sc.nextDouble();
                        account.deposit(amt);
                    } 
                    else 
                    {
                        System.out.println("Account not found!");
                    }
                    break;

                case 2: // Withdraw
                    System.out.print("Enter Account Number: ");
                    accNum = sc.nextInt();
                    account = findAccount(accounts, accNum);
                    if (account != null) 
                    {
                        System.out.print("Enter amount to withdraw: ");
                        double amt = sc.nextDouble();
                        account.withdraw(amt);
                    } 
                    else 
                    {
                        System.out.println("Account not found!");
                    }
                    break;

                case 3: // Change Address
                    System.out.print("Enter Account Number: ");
                    accNum = sc.nextInt();
                    sc.nextLine();
                    account = findAccount(accounts, accNum);
                    if (account != null) 
                    {
                        System.out.print("Enter new address: ");
                        String newAddress = sc.nextLine();
                        account.changeAddress(newAddress);
                    } 
                    else 
                    {
                        System.out.println("Account not found!");
                    }
                    break;

                case 4: // Show all accounts
                    for (Bank acc : accounts) 
                    {
                        acc.show();
                    }
                    break;

                case 5:
                    System.out.println("Exiting program...");
                    break;

                default:
                    System.out.println("Enter a valid choice!!");
            }
        } while (choice != 5);

        sc.close();
    }

    // Method to find account by account number
    private static Bank findAccount(Bank[] accounts, int accNum) 
    {
        for (Bank acc : accounts) 
        {
            if (acc.getAccountNum() == accNum) 
            {
                return acc;
            }
        }
        return null;
    }
}