Java IDE Setup, First Program & main() Method Explained

Introduction

To start programming in Java, you need:

A Java IDE (Integrated Development Environment)
A basic understanding of how Java programs are written
Knowledge of the main() method, where every Java program starts

This lesson explains everything step by step, assuming no prior programming experience.

What Is an IDE?

An IDE (Integrated Development Environment) is a software tool that helps you:

Write Java code
Detect errors
Run Java programs easily

Think of an IDE as a smart workspace designed for programmers.

Popular Java IDEs for Beginners

There are many IDEs available, but beginners usually choose one of these three.

IntelliJ IDEA

Why Use IntelliJ?

Very beginner-friendly
Smart code suggestions
Easy project setup

Best For

Students
Beginners
Professional Java developers

Recommended if you want a smooth learning experience.

Eclipse IDE

Why Use Eclipse?

Free and open-source
Widely used in companies
Strong Java support

Best For

Learning core Java
Enterprise-level development

VS Code (Visual Studio Code)

Why Use VS Code?

Lightweight and fast
Supports many languages
Needs Java extensions

Best For

Beginners who want a simple editor
Multi-language learners

Which IDE Should You Choose?

IDE	Difficulty	Recommendation
IntelliJ IDEA	Easy	⭐ Best for beginners
Eclipse	Medium	Good for Java focus
VS Code	Medium	Lightweight option

Setting Up a Java IDE

Step 1: Install Java JDK

Before installing any IDE, make sure Java JDK is installed.

Check using:

java -version

Step 2: Download and Install IDE

Download IntelliJ / Eclipse / VS Code
Follow on-screen installation steps
Open the IDE after installation

Step 3: Create a New Java Project

Choose New Project
Select Java
Set project name
Choose JDK location

Writing Your First Java Program

The traditional first program in Java is Hello World.

Your First Java Code

class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

Understanding Java Program Structure

Let’s break this program into simple parts.

1. Class Declaration

class HelloWorld {
}

Every Java program must have at least one class
Class name should match the file name

Think of a class as a container for code.

2. main() Method

public static void main(String[] args) {
}

This is the starting point of a Java program
Without main(), Java cannot run the program

Java always starts execution from main().

3. Statements Inside main()

System.out.println("Hello, World!");

Prints text on the screen
Used to display output

main() Method Explained

Why Is main() Important?

The main() method tells Java:

“Start running the program from here.”

Breaking Down main()

public static void main(String[] args)

Keyword	Meaning (Simple)
public	Java can access this method
static	No object needed to run
void	Returns nothing
main	Program starting point
String[] args	Command-line inputs

Beginners don’t need to memorize this now—just understand its purpose.

How Java Program Runs

Java looks for the main() method
Executes code line by line
Displays output
Program ends

Real-Life Analogy

Think of a Java program like a movie:

Class → Movie file
main() method → Play button
Statements → Scenes in the movie

Without pressing Play, nothing happens.

Frequently Asked Questions (FAQs)

Q1. Can Java program run without main()?

No. Java always starts execution from main().

Q2. Which IDE is best for beginners?

IntelliJ IDEA is the easiest for beginners.

Q3. Do I need an IDE to write Java programs?

Not required, but IDEs make learning much easier.

Q4. Why is Hello World used first?

It is the simplest way to understand program execution.

Q5. Can I write multiple classes in one Java program?

Yes, but beginners should start with one class.