OOPs concepts in Java

Object-oriented programming System (OOPs concepts in Java) is a programming paradigm/model based on the concept of “objects”. Object-Oriented Programming is a methodology to design a program using classes and objects. A class that contains data and methods. Let’s understand all the OOPs concepts in Java in detail.

Here is the table content of the article will we will cover this topic.
1. What is a class?
2. What is an object?
3. Constructor in java?
4. Inheritance in java(Is-A relationship)?
5. Polymorphism in Java?
6. Abstraction in Java?
7. Encapsulation in Java?

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Purpose of OOPs concepts in Java

By using OOPs concepts in a programming language you can increase the flexibility and maintainability of programs. OOPs provides many concepts, such as inheritancedata bindingpolymorphism, etc.

We will cover each feature of OOPs in detail:


class is the basic concept of OOPs. A class defines as a blueprint/prototype. You can create an individual object by use of a class. A class can represent the set of properties and methods that are common for all the objects of a class. For more details.


Every entity is an object. Each entity has some properties and behavior. In the same manner, the object has also properties and behaviors. In technical terms, properties are the variables and behavior are the methods. For more details.


A constructor looks like a method but it’s not a method. It has the same name as its class, and it doesn’t return any value. A constructor uses to initialize an object state. Whenever we create an object then the constructor is called.  At the time of calling the constructor, memory for the object is allocated in the memory. For more details.


It is an important concept/feature of Object-Oriented Programming. Inheritance is a  mechanism by which one class can acquire/inherit the features(fields and methods) of another class. Java provides the concept of inheritance. It means in java one class can inherit the variables and methods of another class. It is also known as the Is-A relationship. For more details.


Polymorphism is the OOPs feature that allows us to perform a single action in different ways. In JAVA we can perform different tasks with a single action. For more details.


Abstraction is the quality of dealing with ideas rather than events.  It is the process by which only the essential(necessary)  details are displayed to the user. The non-essential units are not displayed to the user. In OOPs, abstraction is a process of hiding the implementation details from the user and only providing the functionality to the user. The user will have information about the object only what he/she can do with an object instead of how it will do. For more details.


Encapsulation is a process of wrapping the data (variables/attributes) and code acting on the data (methods/behavior) into a single unit. It is a mechanism that binds the variables and methods together. If you are creating a class, it means you are doing encapsulation. We can create a fully encapsulated class in Java by making all the data members of the class private. In encapsulation, the variables of a class are not accessible from outside the class. because they are hidden in other classes. These variables can access only by the methods in which declared in the same class. We can  Therefore, it is also known as data hiding. For more details.

OOPs concepts in Java

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