Object Oriented Concept

Encapsulation

Data hiding and access control

Inheritance

Code reuse and hierarchical relationships

Polymorphism

Method overloading and overriding

Abstraction

Abstract classes and interfaces

Access Modifiers

Public, private, protected, and default

Method Overriding

Runtime polymorphism implementation

Method Overloading

Compile-time polymorphism

Static Keyword

Static variables and methods

Final Keyword

Final classes, methods, and variables

Interface

Multiple inheritance and contracts

Abstract Class

Partial implementation and inheritance

Exception Handling

Try-catch and custom exceptions

Design Patterns

Common OOP solutions