set up reactjs 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: reactjs install

npm install -g create-react-app -> install create react app tools
create-react-app app01 -> create your first projects app001