Constellators

Presented by the

Classes and Methods

In Java, classes and methods are basic concepts of Object Oriented Programming (OOPs) that are used to represent real-world concepts and entities. They’re necessary to make game code functional and more manageable.

TO FIND THIS LESSON (pages repository): Search -> “Constellators - Classes and Methods Lesson” -> Select the most recent one (should be 10/02/25)

What are Classes?

Serves as a blueprint or a template for creating objects
Defines the structure and behavior that objects of that class will possess
Encapsulates data (variables), and methods (functions) will operate on that data
Analogy: cookie cutter (class defines the shape and properties of the cookie, but not the cookie’s taste)

What are Methods?

A function that is stored as a property of an object
Analogy:
Are accessed using dot notation
```
objectName.methodName()
```
The this keyword within a method refers to the object itself, allowing the method to access and modify the object’s properties.

Example:

// This is a method
  fullName: function() {
    return this.firstName + " " + this.lastName;
  },

Summary:
Classes: blueprints for creating objects, defining the properties and methods (functions) that an object will have.
Methods: functions that belong to a class, defining the behavior of an object to perform a specific action.

Popcorn Hack 1

Go to the HW file that you can access here. Download to your student/portfolio repository and complete Popcorn Hack 1.

Examples of Classes and Methods in OOP Breakout

Class: paddle
Methods: move_left(), move_right(), draw()

Class: ball
Methods: move(), bounce(), draw()

// Ball class
  class Ball extends GameObject {
    constructor(x, y, radius = 8) {
      super(x, y);
      this.radius = radius;
      this.dx = 4;
      this.dy = -4;
      this.color = "#ad6bebff";
    }
  }

Class: brick
Methods: draw (), destroy ()

Class: game
Methods: check_collisions (), update (), draw ()

General Example

class Car {
  // The constructor method is called when a new object is created from the class.
  constructor(make, model, year) {
    this.make = make; // Property
    this.model = model; // Property
    this.year = year; // Property
  }

  // A method defined within the class
  drive() {
    console.log(this.make + this.model + " is driving...");
  }

  // Another method
  getCarInfo() {
    console.log("This is a " + this.make + this.model + this.year);
  }
}

// Creating an instance (object) of the Car class
const myCar = new Car("Toyota", "Camry", 2023);

// Calling methods on the instance
myCar.drive(); // Output: Toyota Camry is driving...
console.log(myCar.getCarInfo()); // Output: This is a 2023 Toyota Camry.

Popcorn Hack 2

Go to the HW file from before and complete Popcorn Hack 2.

Homework

Complete the homework and submit to this form. Due 10/6/25 at 11:59pm.