? Java main() Method in Detail

? Quick Overview

The main() method is the entry point of any Java application. When you run a Java program, the JVM starts execution from this method. Without it, a Java program cannot run independently.

? Key Concepts

Entry point of Java program
Must be public and static
Returns void
Accepts command-line arguments
Called automatically by JVM

? Syntax / Theory

The standard syntax of the Java main() method is fixed so that the JVM can locate and execute it correctly. Each keyword has a specific purpose.

public → Accessible by JVM from anywhere
static → Can be called without creating an object
void → Does not return any value
String[] args → Stores command-line arguments

? View Code Example

// Basic structure of main method in Java
public class MainExample {
public static void main(String[] args) {
System.out.println("Hello, Java!");
}
}

? Live Output / Explanation

? Output

When the program runs, the JVM finds the main() method and executes the statement inside it. The text Hello, Java! is printed on the console.

? More Variations of main()

? View Code Example

// main method with command-line arguments
public class ArgsExample {
public static void main(String[] args) {
System.out.println("First argument: " + args[0]);
}
}

? Tips & Best Practices

Always keep the method signature exactly correct
Use meaningful class names
Handle command-line arguments safely
Keep main() simple and delegate logic to other methods

? Try It Yourself

Create a program that prints your name using main()
Pass two numbers as arguments and print their sum
Check what happens if public is removed
Experiment with multiple classes having main()