app.js
import React from 'react'; const App = () => { return ( <div> 我是App </div> ); }; export default App;
index.js
import React from 'react'; import ReactDOM from 'react-dom/client'; import App from "./App"; const root = ReactDOM.createRoot(document.getElementById('root')); root.render( <React.StrictMode> <App/> </React.StrictMode> );
