reactjs giving error Uncaught TypeError: Super expression must either be null or a function, not undefined

Question!

I am using reactjs.

When I run the code below the browser says:

Uncaught TypeError: Super expression must either be null or a function, not undefined

Any hints at all as to what is wrong would be appreciated.

First the line used to compile the code:

browserify -t reactify -t babelify examples/temp.jsx  -o examples/public/app.js

And the code:

var React = require('react');

class HelloMessage extends React.Component {
  render() {
    return <div>Hello </div>;
  }
}

UPDATE: After burning in hellfire for three days on this problem I found that I was not using the latest version of react.

Install globally:

sudo npm install -g [email protected]

install locally:

npm install [email protected]

make sure the browser is using the right version too:

<script type="text/javascript" src="react-0.13.2.js"></script>

Hope this saves someone else three days of precious life.



Answers

you can use super() class in constructor method when you extend the React class and initialize new instance variables in your custom class [HelloMessage, in your case] you have to first override the parent React class constructor.

var React = require('react');

class HelloMessage extends React.Component {
  constructor() {
    super();
  }
  render() {
    return 


If you are receiving this error and are using Browserify and browserify-shim (like in a Grunt task), you might have experienced a dumb moment like I did where you unintentionally told browserify-shim to treat React as already part of the global namespace (for example, loaded from a CDN).

If you want Browserify to include React as part of the transform, and not a separate file, make sure the line "react": "global:React" does not appear in the "browserify-shim" section in your packages.json file.



Using Babel (5.8) I get the same error if I try to use the expression export default in combination with some other export:

export const foo = "foo"
export const bar = "bar"
export default function baz() {}
By : Griffosx


This video can help you solving your question :)
By: admin