源代码:
<!DOCTYPE html> <html> <body> <form id="frm1" action="demo-form"> First name: <input type="text" name="fname" value="Donald"><br> Last name: <input type="text" name="lname" value="Duck"><br> <input type="submit" value="Submit"> </form> <p>The number of elements in "frm1" are: <script> document.write(document.getElementById("frm1").length); </script> </p> </body> </html>
运行结果：