Abstraction

What is abstraction :

1. Abstraction means hiding implementation details and showing only essential features to the user.

How to achieve abstraction :

1. Using abstract keyword

Where you used abstract keyword :

1. We can use abstract keyword in class level and method level.

Can an abstract class have:

Constructors? ✅
Private methods? ✅
Static methods? ✅
Final methods? ✅

Answer : Yes

Notes :

1. abstract class does not have method definition.

2. We can't create object directly.

Can we create an object of an abstract class?

1. Answer: ❌ No But reference can be created

BankService service = new UPIService();

Can an abstract class have instance variable ?

Answer : Yes