This example demonstrates how to integrate React with D3 by rendering a simple text message. It uses React’s `useRef` and `useEffect` hooks to access a DOM element, then applies D3’s `select` function to set the element’s text content to “Hello D3 & React.” The app is mounted via `createRoot` from `react-dom/client`, with D3 v7 and React 19 imported through an import map in the HTML file. The visualization highlights the minimal setup needed to combine React’s component model with D3’s DOM manipulation utilities.