To run this code, you need to install node js or npm. My assumption is the latest version.
Navigate to the terminal / cmd location to copy this project, and clone the project from github repository.
$ cd {YOUR_DIRECTORY}
$ git clone https://github.com/agunbuhori/socket-io-chat-app.git
$ cd socket-io-chat-app
$ node index.js
Open the web browser and go to the http://localhost:3000