在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(cainiaoplay.com)</title>
</head>
<body>

<p id="demo">单击按钮显示今天周几</p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction(){
	var d = new Date();
	var weekday=new Array(7);
	weekday[0]="周日";
	weekday[1]="周一";
	weekday[2]="周二";
	weekday[3]="周三";
	weekday[4]="周四";
	weekday[5]="周五";
	weekday[6]="周六";
	var x = document.getElementById("demo");
	x.innerHTML=weekday[d.getDay()];
}
</script>

</body>
</html>
源代码

动行结果
