OOP’s In Java

Object oriented programming in java in detail

Object-oriented programming (OOP) is a programming paradigm that revolves around the concept of “objects,” which can contain data in the form of fields (attributes or properties) and code in the form of procedures (methods or functions). Java is a popular programming language that supports OOP principles. Here’s an overview of key OOP concepts in Java:

Classes and Objects:

Class:

A class is a blueprint for creating objects. It defines the attributes (fields) and behaviors (methods) that objects of the class will have.

Object:

An object is an instance of a class. It represents a real-world entity with a set of properties and behaviors.

Encapsulation:

Encapsulation is the concept of bundling data (attributes) and methods that operate on the data into a single unit (a class). It hides the internal state of an object from the outside world and only exposes a controlled interface for interacting with the object.

Inheritance:

Inheritance is a mechanism where a new class (derived class or subclass) is created based on an existing class (base class or superclass). The subclass inherits the attributes and methods of the superclass, allowing code reuse and the creation of a hierarchy of classes.

Polymorphism:

Method Overloading:

Method overloading allows a class to have multiple methods with the same name but different parameters. The correct method is chosen at compile time based on the arguments provided.

Method Overriding:

Method overriding occurs when a subclass provides a specific implementation for a method that is already defined in its superclass. The method in the subclass overrides the method in the superclass.

Abstraction:

Abstraction is the concept of hiding complex implementation details and showing only the essential features of an object. In Java, abstraction is achieved through abstract classes and interfaces.

Class Members:

Fields:

Fields are variables that store the state of an object.

Methods:

Methods are functions that define the behavior of an object.

Constructors:

Constructors are special methods used for initializing objects. They have the same name as the class and do not have a return type.

Access Modifiers:

Access modifiers control the visibility of classes, fields, and methods. Java provides four access modifiers:

public:

accessible from any other class.

protected:

accessible within the same package or by subclasses.

default (no modifier):

accessible only within the same package.

private:

accessible only within the same class.

Interfaces:

Is define a contract for classes to implement. They contain abstract methods that must be implemented by classes that implement the interface. Interfaces are used to achieve abstraction and multiple inheritance in Java.

Packages:

Packages are used to organize related classes and interfaces. They provide a way to group related classes and avoid naming conflicts.

In Java, OOP is at the core of the language’s design, making it a powerful tool for building modular, reusable, and maintainable applications.