Uncaught ReferenceError: React is not defined

Question

I am trying to make ReactJS work with rails using this tutorial. I am getting this error:

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Uncaught ReferenceError: React is not defined

Answer 1

The displayed error

after that import react

Finally import react-dom

if error is react is not define,please add ==>import React from 'react';

if error is reactDOM is not define,please add ==>import ReactDOM from 'react-dom';