Express.js Tutorial

Express.js is a minimal and flexible Node.js web application framework that provides a list of features for building web and mobile applications easily. It simplifies the development of server-side applications by offering an easy-to-use API for routing, middleware, and HTTP utilities.

• Built on Node.js for fast and scalable server-side development.
• Simplifies routing and middleware handling for web applications.
• Supports building REST APIs, real-time applications, and single-page applications.
• Provides a lightweight structure for flexible and efficient server-side development.

Learn how to install Node.js on Windows, Linux, and macOS, and also how to Setup Express in a Node project.

First Express.js Program

Here’s how you can start with a basic Express.js application:

// Import Express
const express = require('express');
const app = express();

// Define a route
app.get('/', (req, res) => {
    res.send('Welcome to the Express.js Tutorial');
});

// Start the server
app.listen(3000, () => {
    console.log('Server is running on http://localhost:3000');
});

It will start a server, and when you visit http://localhost:3000, it will display

Welcome to the Express.js Tutorial

In this example:

• Express is imported using require('express'), and an app instance is created with express().
• A route is defined using the app.get() method, which responds with a message when the root URL (/) is accessed.
• The app.listen() method starts the server and listens on port 3000 for incoming requests.

Express Basic

Express.js is a minimal and flexible Node.js framework used to build web applications and APIs. It's known for its simplicity and high flexibility in handling HTTP requests.

• Introduction
• Steps to create Express Application
• Design first Application using Express
• How to Structure my Application in Express JS 
• Unique features of Express
• How to send response from server to client using Node and Express ?
• Why Express ‘app’ and ‘server’ files kept separately ?
• How to implement JWT authentication in Express app
• How to expire session after 1 min of inactivity in express-session of Express JS
• Express Error Handling

Express Functions

Explore the essential functions that make Express flexible and powerful. Learn how to handle various HTTP request methods and middleware.

• Express express() Function
• express.raw() Function
• express.Router() Function
• express.static() Function
• express.text() Function
• express.urlencoded() Function
• express() function Complete Reference

Express Applications Function

Understand the properties and methods of Express applications that allow configuration and response handling.

• app.locals Property
• app.mountpath Property
• Mount Event
• app.all() Function
• app.delete() Function
• app.disable() Function
• app.disabled() Function
• app.enable() Function
• app.enabled() Function
• Application Complete Reference

Express Requests Function

Get to know the request properties and methods used to handle incoming requests and extract data.

• req.app Property
• req.baseUrl Property
• req.body Property
• req.cookies Property
• req.fresh Property
• req.accepts() Function
• req.acceptsCharsets() Function
• req.acceptsEncodings() Function
• req.acceptsLanguages() Function
• Request Complete Reference

Express Response Function

Learn how to respond to HTTP requests with different status codes, cookies, and other HTTP headers.

• res.app Property
• res.headersSent Property
• res.locals Property
• res.append() Function
• res.attachment() Function
• res.cookie() Function
• res.clearCookie() Function
• res.download() Function
• res.end() Function
• Response Complete Reference

Express Router Function

Understand how to create and use routers to define reusable routing logic.

• router.all() Function
• router.METHOD() Function
• router.param() function
• router.route() Function
• router.use() Function
• Router Complete Reference

Express Advanced Topics

After learning routing and basic concepts, let's explore some advanced topics like middleware, authentication, and integrating Express with other technologies.

• Node vs Express
• HTTP request and response cycle
• Middlewares in Express
• How to update record in Cassandra using Express 
• What is the use of next() function in Express JS
• How to create custom middleware in express
• Why Express is used in Web Development
• What is Express Generator
• Express HTTP methods
• How to create routes using Express and Postman?
• Why Express Is Used For Enterprise App Development
• REST API using the Express to perform CRUD
• What is express-session middleware in Express

Express.js For Interview

• Top 50 Express.js Interview Questions and Answers
• Express JS Exercises, Practice Questions and Solutions

Features of Express

1. Middleware and Routing: Define clear pathways (routes) within your application to handle incoming HTTP requests (GET, POST, PUT, DELETE).
2. Minimalistic Design: Express.js follows a simple and minimalistic design philosophy. This simplicity allows you to quickly set up a server, define routes, and handle HTTP requests efficiently.
3. Flexibility and Customization: Express.js doesn’t impose a strict application architecture. You can structure your code according to your preferences.
4. Templating Power: Incorporate templating engines like Jade or EJS to generate dynamic HTML content, enhancing user experience.
5. Static File Serving: Effortlessly serve static files like images, CSS, and JavaScript from a designated directory within your application.
6. Node.js Integration: Express.js seamlessly integrates with the core functionalities of Node.js, allowing you to harness the power of asynchronous programming and event-driven architecture.

Applications of Express

Express.js empowers you to construct a wide array of web applications. Here are some captivating examples:

• RESTful APIs: Develop robust APIs that adhere to the REST architectural style, enabling communication with other applications and front-end interfaces.
• Real-time Applications: Leverage Express.js's event-driven nature to create real-time applications like chat or collaborative editing tools.
• Single-Page Applications (SPAs): Craft SPAs that fetch and update content dynamically on the client-side, offering a seamless user experience.

Express.js vs Other Frameworks