what is ... in react js code example

Example 1: what is react

This is a formatted version of Komadori's answer 
(https://tinyurl.com/Komadori)
React is a JavaScript library for building user interfaces. 
It is maintained by Facebook and a community of 
individual developers and companies. 
React can be used as a base in the development of single-page 
or mobile applications.

Example 2: react js documentation

//With node and npm already installed for basic start

npx create-react-app my-app-name

// if you want to use npm 

npx create-react-app my-app-name --npm

//if you want to use typescript 

npx create-react-app my-app-name --template typescript

yarn start // app will be hosted on localhost:3000

/* start making changes at ./my-app-name/src/App.js
	React documentation: https://reactjs.org/docs/hello-world.html
*/