Lecture 14: Introduction to Node Js

Node.js is a powerful tool for building server-side applications. It is built on Chrome’s V8 JavaScript engine and provides a way to run JavaScript on the server. In this lecture, we will explore the basics of Node.js and how to use it to create web applications and APIs.

What is Node.js?

Node.js is an open-source, cross-platform JavaScript runtime environment that allows developers to build server-side and networking applications. It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, making it ideal for data-intensive real-time applications.

How to Get Started with Node.js

To get started with Node.js, you will need to install the Node.js runtime on your computer. You can download the installer from the Node.js website and follow the installation instructions to set it up on your system. Once installed, you can use the Node Package Manager (npm) to install additional modules and packages to extend the functionality of Node.js.

Creating a Simple Node.js Application

Let’s create a simple “Hello World” application with Node.js. First, create a new file called “app.js” and add the following code:

        const http = require('http');
        
        const server = http.createServer((req, res) => {
            res.writeHead(200, {'Content-Type': 'text/plain'});
            res.end('Hello Worldn');
        });
        
        server.listen(3000, '127.0.0.1', () => {
            console.log('Server running at http://127.0.0.1:3000/');
        });
    

Save the file and open a terminal or command prompt. Navigate to the directory where the file is saved and run the following command:

        node app.js
    

You should see a message indicating that the server is running at http://127.0.0.1:3000/. When you open a web browser and navigate to that address, you should see the text “Hello World” displayed on the page.

Conclusion

Node.js is a powerful platform for building server-side applications with JavaScript. In this lecture, we covered the basics of Node.js and how to get started with creating a simple application. There is much more to learn about Node.js, including how to use it with frameworks like Express and how to build APIs and real-time applications. As you continue to explore Node.js, you will discover the many benefits it offers for building scalable and efficient server-side applications.