HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>queryCommandState multi</title>
  <style>body{font-family:system-ui,sans-serif;margin:1rem;}#editor{border:1px solid #ccc;padding:0.75rem;min-height:3rem;margin:0.5rem 0;}</style>
</head>
<body>
  <div id="editor" contenteditable="true"><b>Bold</b>, <i>italic</i>, and plain text</div>
  <button id="probe" type="button">Probe selection state</button>
  <pre id="out">Select text, then click Probe.</pre>
  <script>
    document.getElementById("probe").addEventListener("click", function () {
      var names = ["bold", "italic", "underline"];
      var lines = names.map(function (name) {
        var state =
          typeof document.queryCommandState === "function"
            ? document.queryCommandState(name)
            : null;
        return name + ": " + String(state);
      });
      document.getElementById("out").textContent = lines.join("\n");
    });
  </script>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

Document.queryCommandState — bold / italic / underline (Try It)