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Problem :

I am using the reactjs.

When I try to run my code the browser says as below:

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

The line used to compile my code:

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

Below is my code:

var myReact = require('react');
class MyHelloMessage extends React.Component {
render() {
return <div>Hello World !! </div>;

Does anyone have any idea on the solution for my issue?

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1 Answer

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Solution :

·    Correct Class Names :

If you are sure that you must extend then please do it from the correctly named class, e.g. React.Component, and not React.component or React.createComponent, you may also need to upgrade your React version.

·     Upgrade React Version :

React is only supporting ES6-style classes since version 0.13.0 (please go through their official blog post on the support introduction here.Before that, while using:

class MyHelloMessage extends React.Component
you were trying to use ES6 keywords (extends) to the subclass from the class which was not defined using ES6 class. Because of this you were facing the strange behavior with the super definitions etc.

So, please TL;DR - update to React v0.13.x. 

·     Circular Dependencies

If one module is importing the another module and the other way around. In this scenario you must refractor the code to avoid it


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