Node.js

Let’s build a basic “Hello World” app together. I’ll guide you through the process with questions at each step.
Step 1: The Environment
First, we need to make sure your machine can speak Node.js. Unlike a browser which has a built-in engine, your computer needs the Node.js runtime installed to execute .js files in your terminal.
To see if you’re ready to go, do you already have Node.js installed on your computer? (You can check by typing node -v in your terminal or command prompt).
* Yes: Great! What version number did it give you?
* No/Not sure: No problem! I can walk you through how to get it set up.

Great, let’s aim for the latest stable version! As of late 2025, that is Node.js v25.2.1 (or v24.12.0 if you prefer the Long Term Support version for stability).
Since you are used to writing code for web pages, let’s create your first Node.js file.
Step 2: Write the Code
In the Node.js world, we don’t need a separate server like Apache to “host” our script. We write a script that creates its own server.
* Create a new folder for your project.
* Inside that folder, create a file named app.js.
* Copy and paste this code into app.js:
<!– end list –>
const http = require(‘http’);

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader(‘Content-Type’, ‘text/plain’);
  res.end(‘Hello World from Node.js!’);
});

server.listen(3000, ‘127.0.0.1’, () => {
  console.log(‘Server running at http://127.0.0.1:3000/&#8217;);
});

Understanding the Code
* require(‘http’): This is like an include in PHP. It loads a built-in module that handles network requests. 📦
* http.createServer: This starts a “listener” that waits for someone to visit your site.
* res.end: This sends the final message back to the browser, similar to an echo in PHP. 📣
Ready to Run?
To start your server, open your terminal/command prompt, navigate to your folder, and type:
node app.js
Once you run that command, what do you see in your terminal, and what happens when you visit http://localhost:3000 in your browser? 🌐
* It worked! I see the message in both places.
* I got an error. (Please share what the error says!)
* Nothing happened. The terminal is just blinking.