<!DOCTYPE html>charset="utf-8"W3Cschool教程(w3cschool.cn)id="myForm"type="number" id="myNumber" value="2"点击按钮返回 number 字段所属的表单id。onclick="myFunction()"点我id="demo"function myFunction() {var x = document.getElementById("myNumber").form.id;document.getElementById("demo").innerHTML = x;}