Building a Web Application with Node.js and Express: A Hello World Tutorial

 To create a web application that prints "Hello World!!" using Node.js and the Express framework, follow these steps:

Step 1: Set up the project

1. Create a new directory for your project.
2. Open a terminal and navigate to the project directory.
3. Initialize a new Node.js project by running the command: npm init -y.
4. Install Express by running the command: npm install express.

Step 2: Create the server file

1. Create a new file named server.js in the project directory.
2. Open server.js in a text editor and add the following code:

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World!!');
});

app.listen(port, () => {
  console.log(`Server is running on http://localhost:${port}`);
});

Step 3: Start the server

1. In the terminal, navigate to the project directory.
2. Run the command: node server.js.

Step 4: Test the application

1. Open a web browser and visit http://localhost:3000.
2. You should see the message "Hello World!!" displayed on the page.

Congratulations! You have created a simple web application using Node.js and Express that prints "Hello World!!" when accessed through a browser.