JNTU B.Tech II OBJECT ORIENTED PROGRAMMING THROUGH JAVA Previous Question Paper (August/September - 2022 - R16)

Object-oriented programming (OOP) is a paradigm based on the concept of objects, which contain data in the form of fields (attributes) and code in the form of procedures (methods). It aims to increase the modularity and reusability of software by organizing code into classes.

The fundamental pillars of OOP are:

• Encapsulation: The bundling of data and the methods that operate on that data into a single unit (class), while restricting direct access to some of an object's components to protect the internal state.
• Abstraction: The process of hiding complex implementation details and showing only the essential features of an object, reducing programming complexity.
• Inheritance: A mechanism where one class (subclass) acquires the properties and behaviors of another class (superclass), promoting code reusability.
• Polymorphism: The ability of an object or method to take on multiple forms. It is implemented through method overloading (compile-time) and method overriding (runtime).

Java is a statically-typed language, meaning all variables must be declared before use. Data types are categorized into two groups:

1. Primitive Data Types: These are the basic building blocks of data, predefined by the language.

• byte: 8-bit signed integer (e.g., byte b = 10;).
• short: 16-bit signed integer (e.g., short s = 100;).
• int: 32-bit signed integer (e.g., int i = 1000;).
• long: 64-bit signed integer (e.g., long l = 100000L;).
• float: 32-bit IEEE 754 floating point (e.g., float f = 10.5f;).
• double: 64-bit IEEE 754 floating point (e.g., double d = 20.99;).
• char: 16-bit Unicode character (e.g., char c = 'A';).
• boolean: Represents true or false values (e.g., boolean flag = true;).

2. Non-Primitive (Reference) Data Types: These refer to objects and are not stored directly in the variable but hold a reference to the memory location. Examples include Strings, Arrays, and Classes (e.g., String str = "Hello";).