Module 30: Abstract Classes

📘 What is an Abstract Class?

An abstract class in Java is a class that cannot be instantiated and may contain abstract methods (methods without a body). It serves as a base for other classes.

📌 Key Points

• Declared using the abstract keyword.
• Can have abstract and non-abstract methods.
• Cannot be instantiated directly.
• Used to define common behavior for subclasses.

🧪 Example: Abstract Class

                    abstract class Animal {
                      abstract void sound(); // abstract method
                    
                      void eat() {
                        System.out.println("This animal eats food");
                      }
                    }
                    
                    class Dog extends Animal {
                      void sound() {
                        System.out.println("Dog barks");
                      }
                    }
                    
                    public class Main {
                      public static void main(String[] args) {
                        Animal a = new Dog();
                        a.sound();  // Output: Dog barks
                        a.eat();    // Output: This animal eats food
                      }
                    }

🎯 Why Use Abstract Classes?

• To provide a base class with common functionality
• To enforce implementation of specific methods in subclasses
• To prevent instantiation of incomplete classes