Blog

Sharing is caring!

Express.js is a minimal and flexible Node.js web application framework that provides robust features for building web and mobile applications. It simplifies developing server-side applications by providing a straightforward API for handling routing, middleware, and server configuration. Whether you’re building a simple RESTful API or a complex web application, Express.js is an excellent choice due to its speed, scalability, and ease of use.

In this guide, we will walk you through the steps to set up a basic Express.js project from scratch. You will learn how to create a project directory, install necessary dependencies, write your first Express application, and run it on your local machine. By the end of this tutorial, you will have a solid foundation to build upon as you explore more advanced features of Express.js.

Step 1: Install Node.js

Before you can start with Express.js, you need to have Node.js installed on your machine. You can download it from the official Node.js website.

Step 2: Create a Project Directory

Open your terminal or command prompt and create a new directory for your project. Navigate into that directory:

mkdir myapp
cd myapp

Step 3: Initialize the Project

Run the following command to create a package.json file, which will manage your project dependencies:

npm init -y

This command initializes a new Node.js project with default settings. You can customize the package.json later if needed.

Step 4: Install Express

Now, install Express as a dependency using npm:

npm install express

This command adds Express to your project and updates the package.json file accordingly.

Step 5: Create Your Main Application File

Create a new file named app.js (or index.js if you prefer) in your project directory. This file will serve as the main entry point for your application.

touch app.js
// for windows
cd . > app.js

Step 6: Write Your First Express Application

Open app.js in your favorite code 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}`);
});

Explanation of the Code:

• Importing Express: The first line imports the Express module.
• Creating an App Instance: const app = express(); creates an instance of an Express application.
• Defining Routes: The app.get() method defines a route for the root URL (/) that sends back a “Hello World!” message.
• Starting the Server: The app.listen() method starts the server on port 3000 and logs a message indicating where it can be accessed.

Step 7: Run Your Application

To run your application, use the following command in your terminal:

node app.js

You should see the output indicating that the server is running:

Server is running on http://localhost:3000

Step 8: Test Your Application

Open your web browser and navigate to http://localhost:3000. You should see “Hello World!” displayed on the page.

Additional Features to Explore

Once you have your basic server running, consider exploring more features of Express.js:

• Routing: Define additional routes using app.get(), app.post(), etc.
• Middleware: Use built-in middleware like express.json() to handle JSON requests.
• Error Handling: Implement custom error handling middleware for better user experience.
• Static Files: Serve static files (like images or CSS) using express.static().

Conclusion

Setting up an Express.js project is straightforward and allows you to quickly build web applications. By following these steps, you have created a basic server that responds with “Hello World!” when accessed. From here, you can expand your application by adding more routes, middleware, and functionality as needed. With its powerful features and flexibility, Express.js is an excellent framework for both beginners and experienced developers looking to create robust web applications. Happy coding!

Sharing is caring!