Importing A Component
This project setup supports ES6 modules thanks to Webpack.
While you can still use require() and module.exports, we encourage you to use import and export instead.
For example:
Button.js
import React, { Component } from 'react';
class Button extends Component {
  render() {
    // ...
  }
}
export default Button; // Don’t forget to use export default!
DangerButton.js
import React, { Component } from 'react';
import Button from './Button'; // Import a component from another file
class DangerButton extends Component {
  render() {
    return <Button color="red" />;
  }
}
export default DangerButton;
Be aware of the difference between default and named exports. It is a common source of mistakes.
We suggest that you stick to using default imports and exports when a module only exports a single thing (for example, a component). That’s what you get when you use export default Button and import Button from './Button'.
Named exports are useful for utility modules that export several functions. A module may have at most one default export and as many named exports as you like.
Learn more about ES6 modules: