<body>
<form action="#" method="post" onsubmit="return false">
<input id="username" type="text" name="username" placeholder="用户名" /><br />
<input type="submit" value="登录" onclick="login()" />
</form>
</body>
<script type="text/javascript">
function login(){
var usernameEle = document.getElementById("username");//得到标签对象
var usernameValue = document.getElementById("username").value;//得到标签对象的内容
console.log(username);
console.log(username.innerHTML);//input不同于div,此写法不可以得到输入内容
console.log(usernameValue)
}
</script> <body>
<form action="
