Popcorn Hacks
Popcorn Hack 1
import java.util.ArrayList;
public class PopcornHack1 {
public static void main(String[] args) {
// TODO: Use Math.pow() to calculate 3^4
double power = Math.pow(3, 4);
System.out.println("3^4 = " + power);
// TODO: Use Math.sqrt() to find square root of 64
double squareRoot = Math.sqrt(64);
System.out.println("Square root of 64 = " + squareRoot);
// TODO: Create ArrayList of Strings
ArrayList<String> colors = new ArrayList<String>();
// TODO: Add 3 colors ("red", "blue", "green")
colors.add("red");
colors.add("blue");
colors.add("green");
// TODO: Print the size
System.out.println("ArrayList size: " + colors.size());
}
}
PopcornHack1.main(null);
3^4 = 81.0
Square root of 64 = 8.0
ArrayList size: 3
Popcorn Hack 2
public class Book {
// TODO: Add 3 attributes (title, author, pages)
private String title;
private String author;
private int pages;
// TODO: Add constructor
public Book(String title, String author, int pages) {
this.title = title;
this.author = author;
this.pages = pages;
}
// TODO: Add displayInfo() method
public void displayInfo() {
System.out.println("Title: " + title);
System.out.println("Author: " + author);
System.out.println("Pages: " + pages);
}
// TODO: Add isLong() method (returns true if pages > 300)
public boolean isLong() {
return pages > 300;
}
// Main method for testing
public static void main(String[] args) {
// TODO: Create a Book object and test all methods
Book myBook = new Book("Java Basics", "John Doe", 350);
System.out.println("Book Information:");
myBook.displayInfo();
System.out.println("\nIs this book long? " + myBook.isLong());
System.out.println("\n--- Testing another book ---");
Book shortBook = new Book("Quick Guide", "Jane Smith", 150);
shortBook.displayInfo();
System.out.println("\nIs this book long? " + shortBook.isLong());
}
}
Book.main(null);
Book Information:
Title: Java Basics
Author: John Doe
Pages: 350
Is this book long? true
--- Testing another book ---
Title: Quick Guide
Author: Jane Smith
Pages: 150
Is this book long? false
Homework Hacks
import java.util.ArrayList;
public class Phone {
// TODO: Add 4 attributes
private String brand;
private String model;
private int batteryLevel;
private ArrayList<String> contacts;
// TODO: Add constructor
public Phone(String brand, String model) {
this.brand = brand;
this.model = model;
this.batteryLevel = 100;
this.contacts = new ArrayList<String>();
}
// TODO: Add displayInfo() method
public void displayInfo() {
System.out.println("Brand: " + brand);
System.out.println("Model: " + model);
System.out.println("Battery Level: " + batteryLevel + "%");
}
// TODO: Add addContact(String name) method
public void addContact(String name) {
contacts.add(name);
System.out.println("Added contact: " + name);
}
// TODO: Add showContacts() method
public void showContacts() {
System.out.println("Contacts (" + contacts.size() + "):");
for (String contact : contacts) {
System.out.println(" - " + contact);
}
}
// TODO: Add usePhone(int minutes) method
public void usePhone(int minutes) {
batteryLevel -= minutes;
if (batteryLevel < 0) {
batteryLevel = 0;
}
System.out.println("Used phone for " + minutes + " minutes. Battery now at " + batteryLevel + "%");
}
}
class PhoneTest {
public static void main(String[] args) {
// TODO: Create 2 Phone objects
System.out.println("=== Creating Phone 1 ===");
Phone phone1 = new Phone("Apple", "iPhone 15");
System.out.println("\n=== Creating Phone 2 ===");
Phone phone2 = new Phone("Samsung", "Galaxy S24");
// TODO: Add 3 contacts to each
System.out.println("\n=== Adding Contacts to Phone 1 ===");
phone1.addContact("Alice");
phone1.addContact("Bob");
phone1.addContact("Charlie");
System.out.println("\n=== Adding Contacts to Phone 2 ===");
phone2.addContact("David");
phone2.addContact("Emma");
phone2.addContact("Frank");
// TODO: Use phones for some minutes
System.out.println("\n=== Using Phones ===");
phone1.usePhone(25);
phone2.usePhone(40);
// TODO: Display all information
System.out.println("\n=== Phone 1 Information ===");
phone1.displayInfo();
phone1.showContacts();
System.out.println("\n=== Phone 2 Information ===");
phone2.displayInfo();
phone2.showContacts();
}
}
PhoneTest.main(null);
=== Creating Phone 1 ===
=== Creating Phone 2 ===
=== Adding Contacts to Phone 1 ===
Added contact: Alice
Added contact: Bob
Added contact: Charlie
=== Adding Contacts to Phone 2 ===
Added contact: David
Added contact: Emma
Added contact: Frank
=== Using Phones ===
Used phone for 25 minutes. Battery now at 75%
Used phone for 40 minutes. Battery now at 60%
=== Phone 1 Information ===
Brand: Apple
Model: iPhone 15
Battery Level: 75%
Contacts (3):
- Alice
- Bob
- Charlie
=== Phone 2 Information ===
Brand: Samsung
Model: Galaxy S24
Battery Level: 60%
Contacts (3):
- David
- Emma
- Frank