HelmetStep3.js

class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      titleName: ''
    };
  }
  changeTitle(ev) {
    this.setState({
      titleName: ev.target.value
    });
  }
  render() {
    return (<div className="App"><h1>{this.state.titleName}</h1><input onChange={this.changeTitle.bind(this)}></input></div>);
    }
}