Node NPM Express Socket.io

Node

• Download / Upgrade Node.js: https://nodejs.org/en/

node Opens a REPL (Read-Eval-Print Loop) in the terminal, allowing you to execute lines of javascript and seeing their result.

node <script-path> Makes Node executes the given script as the "main" file.

NPM

npm init Sets up initial package.json in the current folder. All the descending directories are considered part of the same project.

npm install <package-name> Installs a npm package.

npm install --save <package-name> Installs an npm package, and saves its version in the project's package.json.

Express

• Express example: https://github.com/expressjs/express/blob/master/examples/hello-world/index.js
• Express params in URL: https://expressjs.com/en/api.html#req
• Express querystring: https://expressjs.com/en/api.html#req.query

Socket.io

• Socket.io Chat example: https://github.com/socketio/socket.io/blob/master/examples/chat/index.js