html - php复选框$_post出来都是on

<code>
<?php $hobby = array('跑步','游泳','篮球','足球');
?>

    <form method="post">
        <p>姓名:<input type="text" name="name"></p>
        <p>爱好：
        <?php foreach($hobby as $v){
                echo "<input type='checkbox' name='hobbyS'/>".$v;
            }
        ?>
        </p>
        <input type="submit" value="提交">
        <input type="reset" value="重置">
    </form>

    <?php if(!empty($_POST)){
                ECHO $_POST['name'];
                echo $_POST['hobbyS'];
        }
    ?>



</code>

<code>
<?php $hobby = array('跑步','游泳','篮球','足球');
?>

    <form method="post">
        <p>姓名:<input type="text" name="name"></p>
        <p>爱好：
        <?php foreach($hobby as $v){
                echo "<input type='checkbox' name='hobbyS'/>".$v;
            }
        ?>
        </p>
        <input type="submit" value="提交">
        <input type="reset" value="重置">
    </form>

    <?php if(!empty($_POST)){
                ECHO $_POST['name'];
                echo $_POST['hobbyS'];
        }
    ?>



</code>