const App = () => {
  return (
  <div>
    <div>Boolean：{ String(true) }</div>
    
    <div>Boolean：{ String(false) }</div>
 
    <div>Null：{ String(null) }</div>

    <div>Undefined：{ String(undefined) }</div>
  </div>
  )
}
const root = ReactDOM.createRoot(document.querySelector('#root'));
root.render(<App />);