“反应”不适用于全球范围

Question

I cannot figure out what is I'm making wrong. Also I had read a several questions on the SOF, but any of them is do not suits me.

I have a stack of errors:

Line 3: 'React' must be in scope when using JSX react/react-in-jsx-scope
Line 4: 'React' must be in scope when using JSX react/react-in-jsx-scope
Line 5: 'React' must be in scope when using JSX react/react-in-jsx-scope
Line 9: 'ReactDOM' is not defined no-undef

 function tick() { const element = ( <div> <h1>Hello, world!</h1> <h2>It is {new Date().toLocaleTimeString()}.</h2> </div> ); ReactDOM.render(element, document.getElementById('root')); } setInterval(tick, 1000); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script> 

Answer 1

Add

import React from 'react'
import ReactDOM from 'react-dom'

in the top of the file.