Prerequisite for Express Js

• Before diving into Express.js, it's beneficial to have a foundational understanding of the following technologies:

• JavaScript: Express.js is a JavaScript framework, so a solid understanding of JavaScript is essential. Knowledge of concepts such as variables, functions, objects, arrays, and asynchronous programming is crucial.

• Node.js: Express.js is built on top of Node.js. Therefore, a good grasp of Node.js is necessary. Familiarize yourself with concepts like modules, event-driven programming, and the Node.js runtime environment.

    const http = require('http');

    const server = http.createServer((req, res) => {

        res.end('Hello, Node.js!');

    });

    server.listen(3000, () => {

        console.log('Server is running on port 3000');

    });

• HTTP Protocol: Understanding the basics of the HTTP protocol is important. Know about HTTP methods (GET, POST, etc.), status codes, request headers, and response headers.

• npm (Node Package Manager): npm is the package manager for Node.js, and it's used to install and manage packages (libraries and tools). Learn how to use npm to install packages, manage dependencies, and run scripts.

    npm init

    npm install express

• Once you have a good foundation in these areas, you can start learning and using Express.js to build web applications and APIs. It's also beneficial to be familiar with concepts like middleware, routing, and server-side templating.

• Remember that hands-on practice is key to mastering these technologies. Create simple projects, experiment with different features of Express.js, and gradually build more complex applications as you become more comfortable with the framework. Additionally, refer to the official Express.js documentation (https://expressjs.com/) for detailed information and examples.