<html>
  <head>
    <meta charset="utf-8" />
  </head>
  <body>
    <ul>
      <li>nowcoder</li>
    </ul>
  </body>
  <script type="text/javascript">
    // 补全代码
    let item = document.querySelector("li");
    item.addEventListener("onclick", (e) => {
      e.stopPropagation();
    });
  </script>
</html>