React is undefined, and I have an error connection

Question

 const { createElement} = React
 const { render } = ReactDOM

const title = createElement(
'h1',
{id: 'title', className: 'header'},
'Hello World'
 )

render(
title,
document.getElementById('react-container')
 )

HTML

    <!DOCTYPE html>
      <html lang="en">
      <head>
      <script src="https://facebook.com/react-15.1.0.js"></script>
      <script src="https://facebook.com/react-dom-15.1.0.js"></script>
      <meta charset="UTF-8">
      <title>Hello World with React</title>
      </head>
    <body>
    <div id = "react-container"></div>
    <script src = "index.js"></script>
    </body>
    </html>

When I enter in my code, the local host:3000 server will not load. It says that React is undefined. Here is what I'm talking about Do I need to install something? I have node.js installed, and was working with it so I'm a bit confused. Thank you!

P.S - I used fb.me in the original script, but had to change it to facebook.com.

Please look the below solution maybe it will help you. https://stackoverflow.com/questions/32070303/uncaught-referenceerror-react-is-not-defined — Asd, Oct 05 '18 at 19:03

score 1 · Accepted Answer · answered Oct 05 '18 at 19:03

It seems like those *.js links are either broken or invalid.

You can use other CDNs (such as UNPKG or cloudflare) as shown below. (same code as yours except script tags)

You can run the code below

 const { createElement} = React
 const { render } = ReactDOM

const title = createElement(
'h1',
{id: 'title', className: 'header'},
'Hello World'
 )

render(
title,
document.getElementById('react-container')
 )

<!DOCTYPE html>
      <html lang="en">
      <head>
<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>
      <meta charset="UTF-8">
      <title>Hello World with React</title>
      </head>
    <body>
    <div id = "react-container"></div>
    <script src = "index.js"></script>
    </body>
    </html>

React is undefined, and I have an error connection

1 Answers1