• Table of Contents

  • 4 Pillars of OOPs in Java
  • 1. Encapsulation
  • 2. Inheritance
  • 3. Polymorphism
  • 4. Abstraction
  • Summary

4 Pillars of OOPs in Java

Object-Oriented Programming (OOP) is a programming paradigm that revolves around the concept of objects.

. Java, being an object-oriented language, follows the principles of OOP. There are four main pillars of OOP in Java that form the foundation of the language. Let’s delve into each of these pillars to understand their significance in Java programming.

1. Encapsulation

Encapsulation is the process of bundling data (attributes) and methods (functions) that operate on the data into a single unit known as a class. This helps in hiding the internal state of an object and only exposing the necessary functionalities to the outside world. In Java, encapsulation is achieved through the use of access modifiers such as public, private, and protected.

• Example:
• public class Car {
• private String model;
• public void setModel(String model) {
• this.model = model;
• }
• public String getModel() {
• return model;
• }
• }

2. Inheritance

Inheritance is a mechanism in which a new class inherits properties and behaviors from an existing class. This promotes code reusability and helps in creating a hierarchy of classes. In Java, inheritance is implemented using the ‘extends’ keyword.

• Example:
• public class Animal {
• }
• public class Dog extends Animal {
• }

3. Polymorphism

Polymorphism allows objects to be treated as instances of their parent class. This means that a single method can have different implementations based on the object it is called upon. In Java, polymorphism is achieved through method overloading and method overriding.

• Example:
• public class Calculator {
• public int add(int a, int b) {
• return a + b;
• }
• public double add(double a, double b) {
• return a + b;
• }
• }

4. Abstraction

Abstraction is the process of hiding the implementation details and showing only the essential features of an object. This helps in reducing complexity and improving code maintainability. In Java, abstraction is achieved through abstract classes and interfaces.

• Example:
• public abstract class Shape {
• public abstract double calculateArea();
• }

Summary

Understanding the four pillars of OOP in Java is crucial for writing efficient and maintainable code. Encapsulation, inheritance, polymorphism, and abstraction form the backbone of Java programming and help in creating robust and scalable applications. By mastering these concepts, developers can leverage the power of OOP to build complex software systems with ease.

For more information on Java programming and OOP principles, check out this link.