面的例子返回了该 checkbox 所属的表单的 id - 在线编辑器

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>蜜蜂教程(mifengjc.com)</title>
  <script>
    function displayResult() {
      var x = document.getElementById("myCheck").form.id;
      alert(x);
    }
  </script>
</head>
<body>

  <form id="form1">
    <input type="checkbox" id="myCheck">你喜欢夏天吗?
  </form>
  <button type="button" onclick="displayResult()">显示包含选择框的表单ID</button>

</body>
</html>
​x
 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>蜜蜂教程(mifengjc.com)</title>
  <script>
    function displayResult() {
      var x = document.getElementById("myCheck").form.id;
      alert(x);
    }
  </script>
</head>
<body>
​
  <form id="form1">
    <input type="checkbox" id="myCheck">你喜欢夏天吗?
  </form>
  <button type="button" onclick="displayResult()">显示包含选择框的表单ID</button>
​
</body>
</html>