HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>enableStyleSheetsForSet null</title>
  <style>body{font-family:system-ui,sans-serif;padding:1.5rem;} pre{border:1px solid #ccc;padding:0.75rem;}</style>
</head>
<body>
  <button id="btn" type="button">Try null argument</button>
  <pre id="out">Click the button</pre>
  <script>
    document.getElementById("btn").addEventListener("click", function () {
      if (typeof document.enableStyleSheetsForSet !== "function") {
        document.getElementById("out").textContent =
          "API missing — remember: null ≠ empty string";
        return;
      }
      document.enableStyleSheetsForSet(null);
      document.getElementById("out").textContent =
        "null call completed with no effect";
    });
  </script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

Document.enableStyleSheetsForSet — null no-op (Try It)