HTML5新增表单属性（HTML5）

<!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>HTML5新增表单属性</title>
    <style>input::placeholder {
            color: blue;
        }</style>

</head>

<body>
    <form action="">

        <input type="search" name="sear" id="" required="required" placeholder="hellow" autofocus="autofocus"
            autocomplete="on">

        <input type="file" name="" id="" multiple="multiple" >
        <input type="submit" value="提交">

    </form>

</body>

</html>