I built this simple chat app to learn Socket.io. I added some features like choosing username, displaying online users, sending and receiveing private messages, "user is writing" notification.

 User must choose unique username to enter the chat app. Usernames are stored in localStorage. If user has any username in localStorage, chat page opens directly.

If user chooses an username that has already been chosen by someone else before, app displays warning message "Username already taken.".

Online users are listed on the left side.

 When user clicks any username on the online users list, messaging page opens. User can send and receive private message.

When user is typing, messaging page displays "Writing..." under the username.

To run this app on your local machine:

1. Clone the repo.
2. Install required dependencies and start server:

cd server
npm install
node server.js

3. Install required dependencies and start React app:

cd client
npm install
npm start

4. You can view the app on http://localhost:3000

• Socket.io
• Node.js
• Express
• React

• Socket.io: https://socket.io/
• Node.js: https://nodejs.org/en/
• Express: https://expressjs.com/
• React: https://reactjs.org/
• Create-React-App: https://create-react-app.dev/