Express.js is a minimal and flexible web application framework for Node.js, designed to build web applications and APIs. It provides a simple and intuitive way to handle HTTP requests, manage routes, and render dynamic content.
Express.js allows developers to create server-side applications using JavaScript, making it easy to build scalable and robust web applications. It provides a set of built-in middleware functions that can be used to perform various tasks such as parsing request bodies, handling cookies, and serving static files.
Here is an example of how to create a basic Express.js server using JavaScript:
const express = require('express'); const app = express(); const port = 3000; app.get('/', (req, res) => { res.send('Hello World!'); }); app.listen(port, () => { console.log(`Server listening at http://localhost:${port}`); });
To run this code, you need to have Node.js installed on your machine. Save the code in a file named server.js, then open a terminal and navigate to the directory where the file is located. Run the following command to start the server:
node server.js
Now, if you open a web browser and visit http://localhost:3000, you will see the message “Hello World!” displayed on the page.
Express.js provides a wide range of features and extensions that can be used to enhance the functionality of your web applications. It has a large and active community, which means you can find plenty of resources, tutorials, and plugins to help you build powerful web applications using Express.js.