代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>demo</title>
</head>
<body>
<h1>今天是星期几？</h1>
<script>
var d = new Date();
var weekday = new Array(7);
weekday[0] = "星期日";
weekday[1] = "星期一";
weekday[2] = "星期二";
weekday[3] = "星期三";
weekday[4] = "星期四";
weekday[5] = "星期五";
weekday[6] = "星期六";
document.write("今天是" + weekday[d.getDay()]);
</script>
</body>
</html>效果：
