Intro to Express.js
Express.js is a web application framework for Node.js. It is designed for building web applications and APIs. Express.js provides a set of features to simplify the process of writing server-side code and handling HTTP requests.
Features of Express.js
- Routing: Express.js provides a simple and straightforward way to define routes for handling different types of HTTP requests (GET, POST, PUT, DELETE, etc).
- Middleware: It allows you to use third-party middleware to add additional functionality to your application, such as authentication, logging, and error handling.
- Template engines: Express.js supports various template engines like EJS, Pug, and Handlebars, which makes it easy to generate HTML dynamically.
- Static file serving: You can serve static files such as images, CSS, and JavaScript using the static middleware.
Getting started with Express.js
To get started with Express.js, you first need to install it using npm:
npm install express
Once you have installed Express.js, you can create a new application and start defining routes and middleware to handle incoming HTTP requests.
Example code
Here’s a simple example of a basic Express.js application:
const express = require('express');
const app = express();
app.get('/', (req, res) => {
res.send('Hello, Express.js!');
});
app.listen(3000, () => {
console.log('Server started on port 3000');
});
In this example, we have created a simple server that listens for incoming GET requests on the root path (‘/’). When a request is received, the server responds with the message “Hello, Express.js!”.
Conclusion
Express.js is a powerful and versatile framework for building web applications and APIs in Node.js. It provides a wide range of features and makes it easy to handle HTTP requests, define routes, and add middleware to your application. If you’re looking to get started with server-side web development in JavaScript, Express.js is definitely worth exploring.
