how to start react js in command code example

Example 1: install react js

npx create-react-app <appname>  //  eg:  npx create-react-app blog
cd <appname>  // cd blog
npm start  //runs on localhost:3000

Example 2: new create react app

npx create-react-app my-app
cd my-app
npm start
//Note:npx on the first line is not a typo — 
//it’s a package runner tool that comes with npm 5.2+.