<input>标签中获得鼠标与否的样式变化——js实现

<!DOCTYPE html>
<html>
<head lang="zh">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta charset="utf-8" />
    <meta content="yes" name="apple-mobile-web-app-capable"/>
    <meta content="yes" name="apple-touch-fullscreen"/>
    <meta content="telephone=no" name="format-detection"/>
    <meta content="black" name="apple-mobile-web-app-status-bar-style">
    <meta content="#ffffff" name="msapplication-TileColor" />
    <meta content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0" name="viewport" />
    <title>采销商品基本信息</title>
    <link rel="stylesheet" href="css/index.css"/>

</head>
<body>

<div class="pox">
    佛得角粉丝卡<span>jkladja</span>放到那送到哪
</div>

<div class="pox-1">
    佛得角粉丝卡<span>jkladja</span>放到那送到哪<input class="pox-text" type="text" name="" value="hello">
</div>

<script type="text/javascript" src="./js/jquery.js"></script>
<script type="text/javascript">

    $("input").focus(function(){
         var aa=$(this).val();
         var bb=$(this)[0].defaultValue;
         if(aa==bb){
            $(this).val("");
         }

    });
     $("input").blur(function(){
         var aa=$(this).val();
         var bb=$(this)[0].defaultValue;
         if(aa==""){
            $(this).val(bb);
         }

    });

</script>

</body>
</html>

注意的是defaultValue是js原生态的属性！要使用$(this)[0].defaultVaue