如何在JavaScript中获取表单元素-木庄网络博客

本文摘自PHP中文网，作者逆旅行人，侵删。

HTML中的表单：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <form action="" name="hello" id="login">
              <input type="text" placeholder="demo@email.com"
              <button>提交</button>
    </form>
</body>
</html>

利用document.forms获取当前页面的所有表单

document.forms[0]获取当前页面的第一个表单
document.forms['hello']通过表单的name属性获取表单
document.forms['login']通过表单的id属性获取表单

   <script>
//form
         console.log(document.forms);
//  <form action="" name="hello" id="login">
         console.log(document.forms[0]);
         console.log(document.forms['hello']);
         console.log(document.forms['login']);
           
         console.log(document.forms.item(0));
         console.log(document.forms.item("hello"));
         console.log(document.forms.item("login"));
 //推荐 id
         console.log(document.forms.namedItem("login"));
         console.log(document.forms.hello);
         console.log(document.forms.login);
 
   </script>