Introduction

What is Java ?

Java is a high-level, object-oriented programming language used for building a wide range of applications. Created by James Gosling in 1995 at Sun Microsystems (later acquired by Oracle), Java follows the "Write Once, Run Anywhere" (WORA) principle, meaning Java programs can run on any platform with a Java Virtual Machine (JVM).

Features

Platform Independent → Runs on Windows, Mac, Linux without modification.
Object-Oriented → Everything in Java is based on classes and objects.
Secure & Robust → Strong memory management & built-in security features.
Multithreading → Supports multiple tasks running simultaneously.
Huge Community Support → Millions of Java developers worldwide.

How Does Java Work ?

Java Code Execution Process:

Write Code → Java code is written in a .java file.
Compile → The javac compiler converts it into bytecode (.class file).
Run on JVM → Java Virtual Machine interprets the bytecode & runs it on any OS.

NOTE: Above 'Java Code Execution Process' need not to learn it is done by the compiler itself.

First Java Program

Here’s a simple Java program to print "Hello, Java!"

// My First Java Program
public class HelloJava {
    public static void main(String[] args) {
        System.out.println("Hello, Java!");
    }
}

Output:

Hello, Java!

Real-World Applications of Java

Java is used in various domains, including:

Web Development - Spring Boot, Hibernate
Android Development - Kotlin & Java
Enterprise Software - Banking, CRM, ERP
Game Development - Minecraft, Runescape
Cloud Computing & Big Data - Hadoop, Apache Spark

Two Minute Drill
Java Overview
A powerful, object-oriented language for cross-platform applications.
Key Concepts:
Object-Oriented: Everything in Java revolves around objects.
Platform-Independent: Write once, run anywhere.
Secure & Reliable: Automatic memory management and high-level security.

What is Java ?

How Does Java Work ?

First Java Program

Real-World Applications of Java

Two Minute Drill Java Overview A powerful, object-oriented language for cross-platform applications. Key Concepts: Object-Oriented: Everything in Java revolves around objects.Platform-Independent: Write once, run anywhere.Secure & Reliable: Automatic memory management and high-level security.

Two Minute Drill

Two Minute Drill
Java Overview
A powerful, object-oriented language for cross-platform applications.
Key Concepts:
Object-Oriented: Everything in Java revolves around objects.
Platform-Independent: Write once, run anywhere.
Secure & Reliable: Automatic memory management and high-level security.