Java OOPs Concepts

Aim of object-oriented Programming

: to implement real-word entities, for example, object, classes, abstraction, inheritance, polymorphism, etc.

OOPs (Object-Oriented Programming System)

Object means a real-world entity, and OOP is a methodology or paradigm to design a program using classes and object.

Object

any entity that has state and behavior is know as an object
can be defined as an instance of a class
can communicate without knowing the details of each other's data or code

-> the only necessary thing is the type of message accepted and the type of response returned by the objects

Class

collections of object is called class
does not consume any space

Inheritance

provides code re-usability
used to achieve runtime polymorphism

Polymorphism

If one task is performed in different ways, it is known as polymorphism
In Java, we use method overloading and method overriding to achieve polymorphism

Abstraction

Hiding internal details and showing functionality is know as abstraction
In Java, we use abstract class and interlace to achieve abstraction

Encapsulation

Binding (or wrapping) code and data together into a single unit are known as encapsulation
A Java class is the example of encapsulation
Java bean is the fully encapsulated class since all the data members are private here