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()methodExecutes 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.
