Object-Oriented Programming, commonly referred to as OOP, is a programming paradigm that is centered around the concept of objects. It is a methodology used to write computer programs that are organized, reusable, and easy to understand. Java is one of the many programming languages that support OOP, making it a popular choice for developing complex applications.
Table of Contents
Pillars of OOP in Java | OOP concepts
Classes and Objects
a class is a blueprint that defines the properties and behaviors of objects. It serves as a template for creating objects and can contain variables, methods, and constructors.
Objects are instances of classes and have unique states and actions which is defined by the values of its instance variables, and can perform actions, which are defined by its methods.
Inheritance
Inheritance in Java allows a class to inherit the properties and behaviors of a parent class. It is implemented using the “extends” keyword. The child class inherits all members of the parent class and can add its own members or override methods of the parent class.
Polymorphism
Polymorphism in Java allows objects of different classes to be treated as objects of a common class.
There are two main types of polymorphism in Java:
- method polymorphism.
- object polymorphism.
Method polymorphism: occurs when a method can be used with objects of different classes, and the correct implementation of the method is determined at runtime.
Object polymorphism: occurs when an object of one class is treated as an object of a different class, and the correct implementation of the object’s methods is determined at runtime.
Abstraction
Abstraction in Java hides complex implementation details and exposes only necessary information to the user. It is implemented using abstract classes and interfaces in Java. An abstract class in Java cannot be instantiated and must be extended by another class, while an interface is a collection of abstract methods that can be implemented by multiple classes. Both allow for defining common behaviors shared across multiple classes.
Encapsulation
Encapsulation is the process of wrapping data and functions within an object, protecting its internal state from external modification. It is one of the core principles of OOP, and helps to ensure that the internal state of an object remains consistent and predictable.
Access Modifiers
Access modifiers are keywords in Java that control the visibility of class members, such as variables and methods. The three main access modifiers are private, public, and protected.
Interfaces
Interfaces are a way to define a common set of behaviors that can be implemented by multiple classes. They allow developers to create flexible and reusable code, and promote code reuse and organization.
Advantages and Limitations of OOP in Java
The use of OOP in Java provides many advantages, including the ability to reuse code, improved code organization, and easier code maintenance. However, there are also limitations to using OOP in Java, including the overhead of creating objects and the increased complexity for large systems.
Conclusion
OOP in Java is a powerful and flexible way to develop complex applications. Incorporating OOP can lead to improved productivity and a better development experience.
