Object-oriented programming (OOP) is a methodology that utilizes classes and objects to facilitate software development and maintenance, incorporating key concepts like inheritance, polymorphism, abstraction, and encapsulation. Classes serve as blueprints for creating objects, each possessing specific attributes and methods, while inheritance allows new classes to acquire properties and behaviors from existing ones. Additionally, methods facilitate communication between objects, and both abstract classes and interfaces are tools used to achieve abstraction and define methods in Java.

1. OBJECT ORIENTED
PROGRAMMING

2. WHAT IS OOP..
Object-Oriented Programming is a methodology or paradigm to design a program
using classes and objects. It simplifies software development and maintenance by
providing some concepts:
Object
Class
Inheritance
Polymorphism
Abstraction
Encapsulation
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3. Class
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A class is the blueprint from which the individual objects are created.
Class are templates that are used to create objects, and to define object data types
and methods
It includes-
attributes (its fields or properties) and the things it can do (behaviours,
methods, operations or features).
A class defines the characteristics of an object.

4. Object
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An Object can be defined as an instance of a class.
An objects have the behaviors of their class.
The class specifies how instances are created and how they behave.
method: a method is an action which an object is able to perform.

5. Method
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Method is behavior of an object
Methods define the abilities of an object
Method usually affects only one particular object.
Method is a collection of statements that are grouped together to perform an operation.

6. Message passing
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When two or more objects communicate with each other that means that those objects are
sending and receiving messages. This is often called Message passing (method calling).
In this example the main function call method myFunction(),and the method is return to main.there is
a communication between main and myFunction()

7. Inheritance
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Inheritance in Java is a mechanism in which one object acquires all the properties and
behaviors of a parent object.
The idea behind inheritance in Java is that you can create new classes that are built
upon existing classes. When you inherit from an existing class, you can reuse methods
and fields of the parent class and additional properties of child class.

8. Inheritance
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9. Abstraction
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Abstraction is a process of hiding the implementation details and showing only
functionality to the user.
It shows only essential things to the user and hides the internal details, for example,
sending SMS where you type the text and send the message. You don't know the internal
processing about the message delivery.
Abstraction lets you focus on what the object does instead of how it does it.
We only wants to watch tv ,not wants to know the user manuel.

10. Encapsulation
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Encapsulation in Java is a mechanism of wrapping the data (variables) and code acting
on the data (methods) together as a single unit.

11. An object behaves differently at different place is called polymorphism.
Polymorphism is briefly described as "one interface, many implementations.
Polymorphism
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12. Method overloading
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two or more methods can have same name if they differ in parameters (different number
of parameters, different types of parameters, or both). These methods are called
overloaded methods and this feature is called method overloading.

13. Method overriding
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if the same method is defined in both the superclass class and the subclass class, then
the method of the subclass class overrides the method of the superclass. This is known
as method overriding.

14. Abstract Class
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A class which is declared as abstract is known as an abstract class. It can have
abstract and non-abstract methods. It needs to be extended and its method implemented.
It cannot be instantiated.
An abstract class must be declared with an abstract keyword.
It can have abstract and non-abstract methods.
It cannot be instantiated.
It can have constructors and static methods also.
abstract method
A method which is declared as abstract and
does not have implementation is known as
an abstract method.

15. Interface
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An interface in Java is a blueprint of a class. It has static constants and abstract
methods.
all the methods in an interface are declared with the empty body, and all the fields
are public, static and final by default. A class that implements an interface must
implement all the methods declared in the interface.
Interface supports multiple inheritance.

16. Abstract class and Interface
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Abstract class and interface both are used to achieve abstraction where we can declare
the abstract methods. Abstract class and interface both can't be instantiated.
Abstract class
.It can have abstract and non-abstract
methods.
.It doesn't support multiple inheritance.
.It can have final, non-final, static and
non-static variables.
.It can provide the implementation of
interface.
.It can extend another Java class and
implement multiple Java interfaces.
.It can be extended using keyword "extends".
.It can have class members like private,
protected, etc.
Interface
.It can have only abstract methods. it can
have default and static methods also.
.It supports multiple inheritance.
.It has only static and final variables.
.It can't provide the implementation of
abstract class.
.It keyword is used to declare interface.
.It can extend another Java interface only.
.It can be implemented using keyword
"implements".
.Members of a Java interface are public by
default.