Abstraction in Java – Abstract Class and Abstract Methods Explained

By Bhau Automation • Learn Abstraction, Abstract Class, and Methods in Java with Real Examples

🎯 What You Will Learn in This Video

• What is Abstraction in Java?
• Understanding Abstract Class and Abstract Methods
• When to use Abstract Class and Interface
• Difference between Abstraction and Encapsulation
• Real-life examples of abstraction in Java
• Complete explanation in Hindi and English

💡 Pro Tip: Use abstraction to hide unnecessary details and show only essential functionality to users.

📘 What is Abstraction in Java?

Abstraction is the process of hiding internal implementation details and showing only the essential features of an object. It focuses on what to do instead of how to do it.

In Java, abstraction can be achieved using:

• Abstract Classes
• Interfaces

🔹 Abstract Class in Java

An abstract class is a class declared with the keyword abstract. It may contain abstract methods (without implementation) and non-abstract methods (with body).

abstract class Vehicle {
    abstract void start(); // Abstract method

    void stop() {
        System.out.println("Vehicle stopped");
    }
}

class Car extends Vehicle {
    void start() {
        System.out.println("Car starts with a key");
    }
}

public class AbstractionExample {
    public static void main(String[] args) {
        Vehicle v = new Car();
        v.start();
        v.stop();
    }
}
  

💡 Output

Car starts with a key
Vehicle stopped
  

🧠 Key Points About Abstract Classes

• An abstract class cannot be instantiated directly.
• It can have both abstract and concrete methods.
• It can contain constructors and static methods.
• It can include final methods that cannot be overridden.

🔸 Abstract Methods

An abstract method is a method declared without a body. Subclasses must provide implementation for all abstract methods of the parent class.

🆚 Abstraction vs Encapsulation

🧩 When to Use Abstract Class vs Interface

• Use abstract class when classes share common functionality or fields.
• Use interface when you want to define a contract that multiple classes can implement.

🎥 Watch the Complete Video Tutorial

👉 Watch on YouTube: Abstraction in Java | Abstract Class & Methods

🎓 Key Takeaways

• Abstraction hides complexity and improves code reusability.
• Abstract classes can contain both abstract and non-abstract methods.
• Use abstraction to focus on essential object behavior.
• Interfaces provide 100% abstraction (before Java 8).
• Helps in designing flexible and scalable systems.

⚡ Next Steps: Try creating your own abstract class and interface to understand their differences in implementation.

🚀 Created with ❤️ by Bhau Automation