<!DOCTYPE html>
<html lang="en-US">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width">
    <title>Object-oriented JavaScript class further exercises</title>
  </head>

  <body>
    <p>This example requires you to enter commands in your browser's JavaScript console (see <a href="https://developer.mozilla.org/en-US/docs/Learn/Common_questions/What_are_browser_developer_tools">What are browser developer tools</a> for more information).</p>

  </body>

    <script>
     