Write a simple java program to display message.

Learn how to create your first Java program with detailed explanation

The Java Program

Here's the complete code for our simple Java program that displays a welcome message:

// Simple Java Program to Display a Message

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Welcome to MCA Java Programming!");
    }
}

🧩 Step-by-Step Explanation

1. The Comment Line

// Simple Java Program to Display a Message

This is a single-line comment that describes the purpose of the program. Comments are ignored by the compiler but help humans understand the code.

2. Class Declaration

public class HelloWorld {

This defines a class named HelloWorld, which is required because every Java program must be inside a class.

Important: The class name HelloWorld must exactly match the filename HelloWorld.java.

3. The Main Method

public static void main(String[] args) {

This is the main method, which acts as the entry point for the program. Let's break down its components:

• public: Makes the method accessible from anywhere
• static: Allows the method to be called without creating an object
• void: Indicates the method doesn't return any value
• String[] args: Parameter that accepts command-line arguments

4. Output Statement

System.out.println("Welcome to MCA Java Programming!");

This prints the message to the console followed by a newline. Breaking it down:

• System.out: The standard output stream
• println(): Prints the message and moves to the next line

To display a different message, replace the text inside the quotation marks.

5. Closing Braces

}

These closing braces mark the end of the main method and the class block.

🖥️ Sample Output

When you run this program, you'll see the following output in your console:

Welcome to MCA Java Programming!

🧠 Key Concepts Covered

Concept	Description
Class Definition	All Java code must be within a class
Main Method	The program starts execution from main()
Output Statement	System.out.println() is used to display output
Comments	Improve readability; ignored during execution
Java Syntax	Use of semicolons, method structure, and curly braces