Java Programming Session Notes

Agenda

• Introduction to Java
• Basics of Object-Oriented Programming (OOP)
• Installing Eclipse and Java
• Setting up the environment

What is Java?

• Java is an Object-Oriented Programming (OOP) Language.
• OOP languages can be categorized into three types:
  • Structured Programming Languages: C, Python.
  • Object-Based Programming Languages: VB, VB Script, Python.
  • Object-Oriented Programming Languages: C++, Java, C, Python.

Object-Oriented Programming (OOP) Concepts

• OOP languages support specific concepts:
  1. Class
  2. Object
  3. Polymorphism
  4. Inheritance
  5. Abstraction
  6. Encapsulation
• Java supports all these OOP concepts, making it a purely object-oriented programming language.

Features of Java

1. Platform Independence:
   • Java can run on any operating system without modification.
   • Write once, run anywhere.
2. Case Sensitivity:
   • Java differentiates between uppercase and lowercase letters.

Important Components of Java

• JDK (Java Development Kit): Required for developing Java applications. It includes the compiler and tools.
• JRE (Java Runtime Environment): Required to run Java applications. It includes the JVM (Java Virtual Machine).
• JVM (Java Virtual Machine): Converts Java code into bytecode, allowing it to be executed on various platforms.

Installation of Java and Eclipse

1. Downloading JDK:
   • Visit Oracle's website to download JDK.
   • Sign up to create an Oracle account.
   • Download the appropriate installer for your OS (Windows/Mac).
   • Follow the prompts to install the software.
2. Setting Java Path:
   • Locate the installation directory (typically in C:\Program Files\Java\jdkX.X.X\bin).
   • Add this path in the system environment variables.
3. Installing Eclipse IDE:
   • Visit Eclipse's official website.
   • Download the latest version of the Eclipse IDE.
   • Follow the installation instructions.

Creating a Java Project in Eclipse

Steps to create a project:

1. Open Eclipse and create a new Java project.
2. Create a new package within the src directory.
3. Create a new class inside the package:
   • The class must include a main method to execute the code.

Example of a Basic Java Program

public class FirstJavaProgram {
    public static void main(String[] args) {
        System.out.println("Welcome to Java");
        // More code can be added here
    }
}

• Print statements:
  • Use System.out.print() or System.out.println() for output.
  • Strings must be enclosed in double quotes.

Naming Conventions and Comments

• Class Naming Conventions:
  • Class names should start with uppercase letters.
  • Cannot start with numbers or contain special characters (except underscores).
• Comments:
  • Single-line comments: // comment
  • Multi-line comments: /* comment */

Conclusion

• Practice setting up the environment and creating a simple Java program.
• Familiarize yourself with the syntax and structure of Java programming.
• Prepare for more advanced concepts in future sessions.