function Example() {
   const [count, setCount] = React.useState(0);
   function handleAlertClick() {
      setTimeout(() => {
         alert('You clicked on: ' + count);
      }, 3000);
   }
   return (<div><p>You clicked {count} times</p>
                       <button onClick={() => setCount(count + 1)}>
                          Click me
                       </button>
                       <button onClick={handleAlertClick}>
                          Show alert
                       </button>
              </div>);}ReactDOM.render(<Example/>,document.querySelector("div"));