HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>document.moveBefore comment</title>
  <style>body{font-family:system-ui,sans-serif;padding:1.5rem;} pre{border:1px solid #ccc;padding:0.75rem;white-space:pre-wrap;}</style>
</head>
<body>
  <!-- This comment should move to the document end -->
  <p>Some content</p>
  <button id="btn" type="button">Move comment with moveBefore</button>
  <pre id="out">Click the button</pre>
  <script>
    document.getElementById("btn").addEventListener("click", function () {
      var out = document.getElementById("out");
      if (typeof document.moveBefore !== "function") {
        out.textContent = "document.moveBefore is not supported";
        return;
      }
      var commentNode = null;
      for (var node of document.querySelector("body").childNodes) {
        if (node.nodeType === 8) {
          commentNode = node;
          break;
        }
      }
      if (!commentNode) {
        out.textContent = "No comment found in body";
        return;
      }
      document.moveBefore(commentNode, null);
      out.textContent =
        "parent is document: " + (commentNode.parentNode === document) +
        "\nlastChild is comment: " + (document.lastChild === commentNode) +
        "\nInspect DevTools — comment should be after the html element";
    });
  </script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

Document.moveBefore — MDN comment move (Try It)