PolymorphismDemo.java

import java.time.LocalDate;

/**
 * The PolymorphismDemo class is a tester that puts different account types in one Account array
 * and calls the same methods on each. Each object responds with its own class's version of the method.
 * It does not write to any files.
 */
public class PolymorphismDemo {
    public static void main(String[] args) {
        Account[] accounts = {
            new Account("BaseExample", 90000001, 500.0),
            new NewAccount("NewExample", LocalDate.of(2000, 1, 1), 500.0),
            new DemoAccess("AccessExample", 90000003, 500.0),
            new DemoSavings("SavingsExample", 90000004, 500.0)
        };

        for (Account account : accounts) {
            System.out.println(account);
            account.deposit(100);   // same call, each class's own version runs
            System.out.println("  after deposit 100:  " + account.getBalance());
            account.withdraw(550);
            System.out.println("  after withdraw 550: " + account.getBalance());
            System.out.println();
        }
    }

    /** AccessAccount that skips the file log, so the demo doesn't touch balanceSheet.txt. */
    private static class DemoAccess extends AccessAccount {
        DemoAccess(String name, int number, double balance) { super(name, number, balance); }
        @Override protected void recordTransaction(String type, double amount) { }
    }

    /** SavingsAccount that skips the file log, so the demo doesn't touch balanceSheet.txt. */
    private static class DemoSavings extends SavingsAccount {
        DemoSavings(String name, int number, double balance) { super(name, number, balance); }
        @Override protected void recordTransaction(String type, double amount) { }
    }
}