算是写出来了吧 很冗长的一大段
<!DOCTYPE HTML>
<html >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>系好安全带,准备启航</title>
<script type="text/javascript">
var mydate=new Date();//获取当前时间
var myyear=mydate.getFullYear();//获取当前年份
var mymonth=mydate.getMonth();//获取当前月份
var myday=mydate.getDate();//获取当前日期
var weekday=["星期日","星期一","星期二","星期三","星期四","星期五","星期六"];//设置星期1-7的数组
var mynum=mydate.getDay(); //返回值储存在变量mynum中
document.write(myyear+"年"+mymonth+"月"+myday+"日"+weekday[mynum]+"<br>"); //输出要求的日期格式
var scoreStr = "小明:87;小花:81;小红:97;小天:76;小张:74;小小:94;小西:90;小伍:76;小迪:64;小曼:76";
//var myarr=scoreStr.substring(3,5)+scoreStr.substring(9,11)+scoreStr.substring(15,17)+scoreStr.substring(21,23)+scoreStr.substring(27,29)+scoreStr.substring(33,35)+scoreStr.substring(39,41)+scoreStr.substring(45,47)+scoreStr.substring(51,53)+scoreStr.substring(57,59);
var myarr=[scoreStr.substring(3,5) ,
scoreStr.substring(9,11) ,
scoreStr.substring(15,17),
scoreStr.substring(21,23),
scoreStr.substring(27,29),
scoreStr.substring(33,35),
scoreStr.substring(39,41),
scoreStr.substring(45,47),
scoreStr.substring(51,53),
scoreStr.substring(57,59)];
var num1=myarr[0];
var num2=myarr[1];
var num3=myarr[2];
var num4=myarr[3];
var num5=myarr[4];
var num6=myarr[5];
var num7=myarr[6];
var num8=myarr[7];
var num9=myarr[8];
var num10=myarr[9];
var add=parseInt(num1)+parseInt(num2)+parseInt(num3)+parseInt(num4)+parseInt(num5)+parseInt(num6)+parseInt(num7)+parseInt(num8)+parseInt(num9)+parseInt(num10)
document.write("班级总分为:"+add);
</script>
</head>
<body>
</body>
</html>