Passing up data from Child Component to Parent Component

App.js

import React from 'react';
import { render } from 'react-dom';
import ChildA from './childA.js';
import ChildB from './childB.js';

class App extends React.Component {
  handleKeyUp() {
    console.log('Event bubbling: Passing up data from Child to Parent component');
  }
  render() {
     return (<div onKeyUp={this.handleKeyUp.bind(this)}>
      <ChildA />
      <ChildB />
     </div>)
  }
}


render(<App />, document.getElementById('root')) 

childA.js

import React from 'react';

const ChildA = () => 
  <div>
    <input type="text" />
  </div>

export default ChildA;

childB.js

import React from 'react';

const ChildB = () =>
  <div>
    <input type="text" />
  </div>

export default ChildB;