代码示例:(标识:htmldom_form_elements_length)
<!DOCTYPE html>
<html>
<body>
<form id="myForm" action="/index/demo/form_current.html">
名字:<input type="text" name="fname" value="Bill"><br>
姓氏:<input type="text" name="lname" value="Gates"><br>
<input type="submit" value="提交">
</form>
<p>请点击“试一试”按钮,显示表单中的元素个数。</p>
<button onclick="myFunction()">试一试</button>
<p id="demo"></p>
<script>
function myFunction() {
var x = document.getElementById("myForm").elements.length;
document.getElementById("demo").innerHTML = "在表单中找到 " + x + " 个元素。";
}
</script>
</body>
</html>