This example demonstrates a minimal integration of React and D3, displaying the text "Hello D3 & React" centered on the page. It uses React’s `useRef` and `useEffect` hooks to obtain a DOM node, then calls D3’s `select` method to set the element’s text content. The rendering occurs through `react-dom/client`’s `createRoot`, with D3 v7 and React 19 imported via an import map in the HTML file.