Session 24

Source Code

import java.util.*;

public class Session24 {
    public static void main(String[] args) {
        System.out.println("Session 24");

        // Menu
        System.out.println("Menu");
        System.out.println("E1 - Example 1");

        // setup Scanner
        Scanner in = new Scanner(System.in);
        System.out.print("Choice: ");
        String choice = in.nextLine();

        // switch choices
        switch (choice) {
            case "E1":
                System.out.println("Example 1");
                example1();
                break;
            case "E2":
                System.out.println("Example 2");
                example2();
                break;
            case "E3":
                System.out.println("Example 3");
                example3();
                break;
            case "E4":
                System.out.println("Example 4");
                example4();
                break;
            case "E5":
                System.out.println("Example 5");
                example5();
                break;
            default:
                System.out.println("Invalid choice");
        }
    }

    // example1 method
    public static void example1() {
        

        // Get a reference to the current song
        

        // Modify the song
        

        // The song inside MusicPlayer is affected
        
    }

    // example2 method
    public static void example2() {
        

        // Modify the returned object directly
        

    }

    // example3 method
    public static void example3() {
        
    }

    // example4 method
    public static void example4() {
        
    }

    // example5 method
    public static void example5() {
        // isPrime
        

        // fibonacci
       

        // gcd
      

    }
}

Song.java

/**
 * The Song class represents a song with a title and duration.
 * This class is used to demonstrate object references in Java.
 */
public class Song {

    /** The title of the song */
    

    /** The length of the song in seconds */
    

    /**
     * Constructs a Song with a title and duration.
     *
     * @param title the title of the song
     * @param duration the length of the song in seconds
     */
    

    /**
     * Returns the title of the song.
     *
     * @return the song title
     */
    
    

    /**
     * Returns the duration of the song.
     *
     * @return the duration in seconds
     */
    
    

    /**
     * Updates the title of the song.
     *
     * @param newTitle the new title
     */
  
  

    /**
     * Extends the duration of the song.
     *
     * @param extraSeconds number of seconds to add
     */
    
    

    /**
     * Returns a string representation of the song.
     *
     * @return song description
     */
    
    
}

MusicPlayer.java

/**
 * The MusicPlayer class represents a music player
 * that keeps track of the currently playing song.
 */
public class MusicPlayer {

    /** The song currently playing */
    

    /**
     * Constructs a MusicPlayer and sets an initial song.
     */
    

    /**
     * Returns the song currently playing.
     * This method returns a reference to the Song object,
     * not a copy.
     *
     * @return the current song
     */
    
}

CityBankAccount.java

/**
 * Represents a bank account at CityBank.
 */
public class CityBankAccount{

    // instance variables
    private double balance;

    /**
     * Constructs a BankAccount with an initial balance.
     *
     * @param initialBalance the starting balance
     */
    

    /**
     * Deposits money into the account.
     *
     * @param amount the amount to deposit
     */
   

    /**
     * Withdraws money from the account.
     *
     * @param amount the amount to withdraw
     */
   

    /**
     * Returns the current balance.
     *
     * @return the account balance
     */
    

}

CityBankCustomer.java

/**
 * Represents a CitiBank customer.
 */
public class Customer {

    // instance variables
    private String name;
    private CityBankAccount account;

    /**
     * Constructs a Customer with a name and an initial account balance.
     *
     * @param name the customer's name
     * @param initialBalance the starting balance
     */
    public Customer(String name, double initialBalance) {
        this.name = name;
        account = new CityBankAccount(initialBalance);
    }

    /**
     * Returns the customer's bank account.
     * This method should return a reference to the BankAccount object,
     * not a copy.
     *
     * @return the customer's bank account
     */
    public CityBankAccount getAccount() {
        // TODO: return the account
        return null;
    }
}

CityBankDemo.java

public class CityBankDemo {
    public static void main(String[] args) {
        // CityBankCustomer c = new CityBankCustomer("Alex", 500.0);

        // Access the same BankAccount through the returned reference
        // CityBankAccount acct = c.getAccount();
        // acct.deposit(200.0);
        // acct.withdraw(50.0);

        // System.out.println(acct.getBalance());
    }
}

User.java

public class User {
    /*
     * Class-wide counter used to generate sequential IDs for all User instances.
     */
    

    /**
     * The unique identifier assigned to this User instance.
     */
    

    /**
     * Creates a new User and assigns it a unique ID from the shared counter.
     * The counter is then incremented so the next User gets a different ID.
     */
    

    /**
     * Returns this user's unique identifier.
     *
     * @return the unique ID for this User
     */
    

    /**
     * Resets the shared ID counter back to 1.
     * This affects IDs assigned to subsequently created User instances.
     */
    
    
}

MathUtilities.java

public class MathUtilities {
    // Class methods - no object needed
    
    // Check if a number is prime
    

    // Calculate nth Fibonacci number (1, 1, 2, 3, 5, 8, 13, ...)
    
    
    // Calculate greatest common divisor using Euclidean algorithm
    
}

Dealership.java

/**
 * The Dealership class represents a car dealership that tracks its inventory,
 * including individual car details and overall inventory statistics.
 * 
 * This class includes instance variables for individual car attributes such as
 * make, model, year, and price, as well as class variables to track total inventory details,
 * including the total number of cars and the total inventory value.
 */
public class Dealership {

    /**
     * The make of the car (e.g., Toyota, Honda, etc.).
     */
   

    /**
     * The model of the car (e.g., Camry, Civic, etc.).
     */
  

    /**
     * The manufacturing year of the car.
     */


    /**
     * The price of the car in dollars.
     */
   

    /**
     * The total number of cars in the dealership’s inventory.
     * This is a class-level variable shared across all objects of this class.
     */
   

    /**
     * The total value of all cars in the dealership’s inventory.
     * This is a class-level variable shared across all objects of this class.
     */
    

    /**
     * Constructs a new Dealership object with the specified attributes.
     * Also updates the total inventory statistics for all cars in the dealership.
     *
     * @param make  The make of the car.
     * @param model The model of the car.
     * @param year  The manufacturing year of the car.
     * @param price The price of the car.
     */
    

    /**
     * Returns the details of the car in formatted string form.
     * For example: "Make: Toyota, Model: Camry, Year: 2020, Price: $30000.00".
     *
     * @return A formatted string containing the car details.
     */
    

    /**
     * Returns the total number of cars in the dealership's inventory.
     *
     * @return The total number of cars.
     */
    

    /**
     * Returns the total value of all cars in the dealership's inventory.
     *
     * @return The total inventory value.
     */
    

    /**
     * Returns the average price of all cars in the dealership's inventory.
     * If there are no cars in inventory, this should return 0.
     *
     * @return The average price of cars in the inventory.
     */
    

    /**
     * The main method to test the functionality of the {@code Dealership} class.
     *
     * @param args Command-line arguments (not used).
     */
    public static void main(String[] args) {
        // Create some cars and add them to the dealership inventory
        

        // Print individual car details
       

        // Print dealership statistics
        
    }
}