Data abstraction is the process of hiding certain details and showing only essential information to the user. Interfaces and Abstract classes. Contains abstract keyword also.

1. ABSTRACTION

2. What is Abstraction ?
• There are four Pillars of OOP i.e. Polymorphism , Abstraction ,
Inheritance and Encapsulation. We’ll explore one of the four pillars of OOP
i.e. Abstraction. Abstraction is one of the key elements of good software
design. In java, abstraction is achieved by interfaces and abstract
classes.
• Abstraction is the art of hiding implementation details from the user and
provide the user with what they want.

3. EXAMPLE OF ABSTRACTION
Let’s try to understand abstraction further, with some real-world
examples.
• All are performing operations on the ATM machine like cash
withdrawal, money transfer, retrieve mini-statement…etc. but
we can't know internal details about ATM.
ABSTRACTION
0-100% Abstract
classes
100 % interface

4. • Any class that contains one or more abstract methods must also
be declared with abstract keyword.
• An abstract method is a method that is declared without an
implementation.
• Abstract Method can only be used in an abstract class, and it
does not have a body .
• It can have constructors and static methods also.
WHAT IS THE PURPOSE OF ABSTRACT CLASSES

5. INTERFACE IN JAVA
• The interface in Java is a mechanism to achieve 100 % abstraction.
• A class can extend only one class.
• An interface can extend another interface.
• But the class can implement more than one interface at a time.
HOW ?
For Example, the user who wants to use the methods of
interface he only knows the classes that implement this interface,
their methods. The information of implementation is completely
hidden from the user.

6. Example :
abstract class Car
abstract void stop();
}
class Civic extends Car{
void stop()
{
System.out.println("Civic Car is Stop on Signal");
}
public static void main(String args[]){
Car obj = new Civic();
obj.stop();
}
}
SYNTAX : abstract void stop();

7. THANK YOU !