Youtube in React: dynamically creating video grids in Home Content

HomeContent.js

/*...*/
import {getMostPopularVideos, getVideosByCategory} from '../../../store/reducers/videos';

class HomeContent extends React.Component {
  /* ... */

  getVideoGridsForCategories() {
    const categoryTitles = Object.keys(this.props.videosByCategory || {});
    return categoryTitles.map((categoryTitle,index) => {
      const videos = this.props.videosByCategory[categoryTitle];
      // the last video grid element should not have a divider
      const hideDivider = index === categoryTitles.length - 1;
      return <VideoGrid title={categoryTitle} videos={videos} key={categoryTitle} hideDivider={hideDivider}/>;
    });
  }
  /* ... */
}