Introduction to Programming Paradigms Module 1

Introduction to Programming Paradigms

• Computers excel in storage, quick recall, and high-speed calculations, but require specific instructions to function.
• Programming provides these instructions, with various approaches known as programming paradigms.

Programming Paradigms

• A programming paradigm is a method used to solve problems with programming languages.

• Procedural Programming:

  • Also called imperative programming, it uses step-by-step instructions.
  • Relies on procedures or subroutines for computations.
  • Examples include C, FORTRAN, and COBOL.

• Object-Oriented Programming (OOP):

  • Models problems as objects and is an extension of procedural programming.
  • Focuses on classes as blueprints for creating objects, which encapsulate attributes and behaviors.
  • First developed in the 1960s with Simula.
  • Other examples: Java, C++, Python, Ruby.

Core Concepts of Object-Oriented Programming

• Objects: Instances that encapsulate attributes (state) and methods (behavior).

• Classes: Blueprints for creating objects, defining common properties among them.

• Inheritance:

  • Allows a subclass to inherit properties and methods from a parent class, promoting code reusability.

• Polymorphism:

  • Enables entities to take on multiple forms or implement one interface in different ways.

• Encapsulation:

  • Bundling data and methods in a class while restricting external access, akin to a medical capsule.

• Abstraction:

  • Hides unnecessary details from users, revealing only essential features.

History of Java

• Originated from the Green Project in 1991, aimed at developing software for consumer electronics, led by James Gosling.
• Initially called Oak, named after an oak tree outside Gosling's office; later renamed Java after a local coffee shop.
• Officially launched in 1995 with the promise of "Write Once, Run Anywhere" (WORA).
• Java became one of the most widely used programming languages by 2010.

Features of Java

• Simple: Excludes complexities like pointers and operator overloading.
• Portable: Applications run on any platform without modification.
• Object-Oriented: Structures everything as objects.
• Secure: Compiles into bytecode, executed in a secure environment to prevent breaches.
• Dynamic: Supports dynamic memory allocation, optimizing performance.
• Distributed: Facilitates remote method invocation for distributed applications.
• Robust: Strong memory management reduces error likelihood.
• High Performance: Uses bytecode and Just-In-Time (JIT) compilation for speed.
• Interpreted: Bytecode translated by the Java Runtime Environment (JRE).
• Multithreaded: Allows concurrent operations in programs.

Structure of a Java Program

• Class Definition:

  • A class serves as a container for attributes and methods.
  • Contains access modifiers (e.g., public) to manage visibility.

• Method Definition:

  • Includes method headers and bodies; specifies if it returns a value (e.g., void).

• Comments:

  • Single-line: // comment
  • Multi-line: /* comment */

Programming Errors in Java

• Syntax Errors: Mistakes in the structure (e.g., missing semicolons).
• Semantic Errors: Logic issues leading to unrecognizable code.
• Runtime Errors: Errors during execution, such as division by zero.

Java Data Types

• Data Types: Classifications for variable values.

• Primitive Data Types: Predefined basic types, include:

  • byte (1 byte), short (2 bytes), int (4 bytes), long (8 bytes), float (4 bytes), double (8 bytes), char (2 bytes), boolean (1 bit).

• Class Data Types: User-defined or provided by Java (e.g., String).

Variables and Constants in Java

• Variable: A memory storage location for a value, which can change.
• Declaration: Syntax includes data type followed by variable name (e.g., int number1;).
• Constant: A fixed value that cannot change, declared using the final keyword, typically formatted in uppercase.

Operators in Java

• Operators: Symbols that perform operations, conditions, or create relational expressions between variables.