7.6 使用Document对象

Document对象是指文档对象，表示在浏览器窗口中显示的页面文档。Document对象既属于BOM对象，也属于DOM对象。Document对象的属性/方法如表所示。

效果图


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h2>浏览某页面的时间</h2>
    <hr>
    <form action="" name="time">
        <p>浏览本页面总共用去
            <input type="text" name="timer" id="" size="6" value="0:00">秒
        </p>
    </form>
    <script>
        var entered = new Date();
        function Timetrack(){
            var now = new Date();
            var seconds = Math.floor((now.getTime()-entered.getTime())/1000);
            var minutes = Math.floor(seconds/60);
            var second = seconds%60;
            var minute = minutes%60;
            document.time.timer.value = minute+":"+second;
            // setTimeout("Timetrack()",1000);
        }
        setInterval(Timetrack,1000);        
    </script>
</body>
</html>