動くかどうかわからん.jsx

class A extends React.Component {
  constructor(props, context) {
    super(props, context);
    
    this.globalCallbackName = 'kdjlwkqe';
    this.ref = React.createRef();
  }

  componentDidMount() {
    global[this.globalCallbackName] = () => new google.maps.Map(this.ref.current, {
      center: {lat: -34.397, lng: 150.644},
      zoom: 8
    });
  }

  componentWillUnmount() {
    delete global[this.globalCallbackName];
  }

  render() {
    return <>
      <div ref={this.ref}></div>

      <script src={`https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=${this.globalCallbackName}`}></script>
    </>;
  }
}