asyncReview.html

  
 <!doctype html>
<html>

<head>
  <meta charset="utf-8" />
  <title>Promises Start</title>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/6.4.0/rxjs.umd.min.js"></script>
</head>

<body>
  <script>
      async function f() {

      let promise = new Promise((resolve, reject) => {
        setTimeout(() => resolve("done!"), 10000)
      });
      console.log("Start")
      let result = await promise; // wait until the promise resolves, can only be used in async (*)

      alert(result); // "done!"
      console.log("Done");
    }

    f();

  </script>
</body>

</html>