block6.javascript

// ...
class Hamburger extends Component {
  constructor(props) {
    super(props);
    this.state = {
      toggleState: 0
    };
    this.handleClick = this.handleClick.bind(this);
  }

  handleClick() {
    this.refs.container.classList.toggle('change');
    this.setState({
      toggleState: this.state.toggleState ? 0 : 1
    });
  }
}
// ...