How to Create a Simple Server with Express.js

Making a server with Express.js is easy and more user-friendly than using Node.js's built-in HTTP module. Let’s break down the main steps to set up a simple server with this popular tool.

Step 1: Set Up Your Work Area

First, make sure you have Node.js on your computer. You can get it from the Node.js official website.

After that, create a new folder for your project:

mkdir my-express-server
cd my-express-server

Next, start your Node.js project by running this command:

npm init -y

This will create a package.json file, which helps keep track of your project and its features.

Step 2: Install Express.js

Now you need to install Express.js. You can do this with npm, which is a package manager for Node.js:

npm install express

Once it's done, your package.json file will show that you have express as one of your project’s tools.

Step 3: Make Your Server File

It’s time to create the main file for your server. Let’s name it server.js:

touch server.js

Open this file in your favorite text editor. Start by adding Express and creating an app:

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

Step 4: Set Up a Simple Route

One cool thing about Express.js is how easy it makes routing. Let’s create a route that responds to a GET request:

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

In this code, when someone visits the main URL (/), the server will reply with “Hello, World!”

Step 5: Start Your Server

To have your server listen for requests, you must choose a port. Developers often use port 3000:

const PORT = 3000;
app.listen(PORT, () => {
  console.log(`Server is running on http://localhost:${PORT}`);
});

Now all the steps we’ve done come together. Run your server by typing this command:

node server.js

You should see a message saying that the server is running.

Step 6: Test Your Server

Let’s see if everything works! Open your web browser and go to http://localhost:3000. You should see “Hello, World!” on the screen!

More Features to Explore

After you get the basics down, you can try out more features that Express.js offers, like:

• Middleware: These are functions that can change the request and response objects.
• Routing: Set up more complex routes with extra details.
• Static Files: Serve things like images and style sheets directly.

Conclusion

Creating a simple server with Express.js is pretty easy! You need to set up your work area, install the tool, create a route, and start your server. With this knowledge, you can learn even more about Express.js and build more advanced back-end applications! Happy coding!