JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II JAVA PROGRAMMING Previous Question Paper (July/August - 2021 - R15)

Object-Oriented Programming (OOP) is a paradigm based on the concept of objects that contain data and code. The key features are:

1. Classes and Objects: A class is a blueprint for creating objects, while an object is an instance of a class containing state and behavior.
2. Encapsulation: The mechanism of wrapping data (variables) and code (methods) together as a single unit, restricting direct access to some of an object's components.
3. Abstraction: The process of hiding complex implementation details and showing only the essential features of an object to the user.
4. Inheritance: A mechanism where one class acquires the properties and behaviors of another class, promoting code reusability.
5. Polymorphism: The ability of an object to take on many forms, achieved through method overloading (compile-time) and method overriding (runtime).

Access modifiers in Java define the scope and visibility of classes, methods, and variables. They are as follows:

1. Private: The access level is limited to the class only. Members marked private cannot be accessed from outside the class.
2. Default (No modifier): Access is restricted to the package level. If no modifier is specified, the member is visible only to other classes within the same package.
3. Protected: Access is available within the same package and by subclasses in different packages. It allows controlled inheritance of members.
4. Public: The access level is global. Members marked public can be accessed from any other class in the application, regardless of the package.