⚛️React setup : the App component

Finally, let's get some real visible code going by starting a new file src/App.js:

/* reactjon/src/App.js */

export default function App() {
  return (
    <div>
      <h1>Hello!</h1>
      <h2>Let's begin our React App!</h2>
    </div>
  );
}

Breaking that down:

• export means we can use this file in other files

• default means that when we import this file elsewhere we do not have to call it App :

/* reactjon/src/index.js */

import { StrictMode } from "react"
import { createRoot } from "react-dom/client"

/* instead of */
// import App from "./App"

/* we can do this because we used "default" in App.js */
import Whatever from "./App"

const rootElement = document.getElementById("root")
const root = createRoot(rootElement)

root.render(
  <StrictMode>
    <Whatever />
  </StrictMode>
)