Module 20: Classes and Objects

🏗️ Understanding Classes

A class is a blueprint for creating objects. It can include fields (attributes) and methods (functions) that define the behavior of objects.

📦 What is an Object?

An object is an instance of a class. When a class is instantiated, memory is allocated and the object is created.

📘 Example: Class and Object

                    class Car {
                      String color;
                      int speed;
                    
                      void drive() {
                        System.out.println("The car is driving.");
                      }
                    }
                    
                    public class Main {
                      public static void main(String[] args) {
                        Car myCar = new Car();
                        myCar.color = "Red";
                        myCar.speed = 120;
                        myCar.drive();
                      }
                    }
                    

🔧 Constructors

Constructors are special methods used to initialize objects. They have the same name as the class and no return type.

                    class Student {
                      String name;
                    
                      Student(String n) {
                        name = n;
                      }
                    
                      void display() {
                        System.out.println("Name: " + name);
                      }
                    }
                    
                    public class Main {
                      public static void main(String[] args) {
                        Student s1 = new Student("Alice");
                        s1.display();
                      }
                    }