1.10 Lesson Homework

Popcorn Hack 1

import java.util.ArrayList;

public class PopcornHack1 {
    public static void main(String[] args) {
        // Use Math.pow() to calculate 3^4
        double power = Math.pow(3, 4);
        System.out.println("3^4 = " + power);

        // Use Math.sqrt() to find square root of 64
        double sqrt = Math.sqrt(64);
        System.out.println("Square root of 64 = " + sqrt);

        // Create ArrayList of Strings
        ArrayList<String> colors = new ArrayList<>();

        // Add 3 colors
        colors.add("red");
        colors.add("blue");
        colors.add("green");

        // Print the size
        System.out.println("Number of colors in the list = " + colors.size());
    }
}


PopcornHack1.main(null);

3^4 = 81.0
Square root of 64 = 8.0
Number of colors in the list = 3

Popcorn Hack 2

public class Book {
    private String title;
    private String author;
    private int pages;

    // Constructor to set all attributes
    public Book(String title, String author, int pages) {
        this.title = title;
        this.author = author;
        this.pages = pages;
    }

    // Method to display all book info
    public void displayInfo() {
        System.out.println("Book Title: " + title);
        System.out.println("Author: " + author);
        System.out.println("Pages: " + pages);
    }

    // Method to check if the book is long
    public boolean isLong() {
        return pages > 300;
    }
}

// --- Test the Book class ---
Book myBook = new Book("Java Basics", "Ahaan Vaidyanathan", 350);

// Call displayInfo()
myBook.displayInfo();


System.out.println("Is the book long? " + myBook.isLong());

Book Title: Java Basics
Author: Ahaan Vaidyanathan
Pages: 350
Is the book long? true

Homework Hack

import java.util.ArrayList;

// --- Phone class ---
public class Phone {
    // Attributes
    private String brand;
    private String model;
    private int batteryLevel;
    private ArrayList<String> contacts;

    // Constructor
    public Phone(String brand, String model) {
        this.brand = brand;
        this.model = model;
        this.batteryLevel = 100; // starts at 100
        this.contacts = new ArrayList<>();
    }

    // Display brand, model, and battery
    public void displayInfo() {
        System.out.println("Brand: " + brand);
        System.out.println("Model: " + model);
        System.out.println("Battery Level: " + batteryLevel + "%");
    }

    // Add a contact
    public void addContact(String name) {
        contacts.add(name);
    }

    // Show all contacts
    public void showContacts() {
        System.out.println("Contacts: " + contacts);
    }

    // Use phone for some minutes
    public void usePhone(int minutes) {
        batteryLevel -= minutes;
        if (batteryLevel < 0) batteryLevel = 0;
    }
}

// --- Test Phone class ---
public class PhoneTest {
    public static void main(String[] args) {
        // Create 2 Phone objects
        Phone phone1 = new Phone("Apple", "iPhone 15");
        Phone phone2 = new Phone("Samsung", "Galaxy S23");

        // Add 3 contacts to each phone
        phone1.addContact("Ahaan");
        phone1.addContact("Bella");
        phone1.addContact("Rudransh");

        phone2.addContact("Arnav");
        phone2.addContact("Nikhil");
        phone2.addContact("Xavier");

        // Use phones for some minutes
        phone1.usePhone(20);
        phone2.usePhone(45);

        // Display all information
        System.out.println("--- Phone 1 Info ---");
        phone1.displayInfo();
        phone1.showContacts();

        System.out.println("\n--- Phone 2 Info ---");
        phone2.displayInfo();
        phone2.showContacts();
    }
}


PhoneTest.main(null);

--- Phone 1 Info ---
Brand: Apple
Model: iPhone 15
Battery Level: 80%
Contacts: [Ahaan, Bella, Rudransh]

--- Phone 2 Info ---
Brand: Samsung
Model: Galaxy S23
Battery Level: 55%
Contacts: [Arnav, Nikhil, Xavier]