点击运行
<!DOCTYPE html> <html> <body> <form id="form1"> <button id="btn1" type="button">HTML</button> </form> <p>单击“试一试”按钮以显示 HTML 按钮所属表单的 id：</p> <button onclick="myFunction()">试一试</button> <p id="demo"></p> <script> function myFunction() { var x = document.getElementById("btn1").form.id; document.getElementById("demo").innerHTML = x; } </script> </body> </html>
运行结果
