<!DOCTYPE??HTML>
<html?>
<head>
<meta?http-equiv="Content-Type"?content="text/html;?charset=utf-8"?/>
<title>系好安全帶,準備啟航</title>
<script?type="text/javascript">
??var?mydate=new?Date();
??var?weekday=["星期日","星期一","星期二","星期三","星期四","星期五","星期六",];
??document.write(mydate.getFullYear()+"年"+parseFloat(mydate.getMonth()+1)+"月"+mydate.getDate()+"日?"+weekday[mydate.getDay()]+"<br>");
?
??
??var?scoreStr?=?"小明:87;小花:81;小紅:97;小天:76;小張:74;小小:94;小西:90;小伍:76;小迪:64;小曼:76";
??var?score1=new?Array;
??var?score2=new?Array;
??var?sum;
??score1=scoreStr.split(";");
??for(var?i=0;i<score1.length;i++){
??????document.write(score1[i]+"<br>")
????score2=score1[i].split("");
????var?a=score2[3]+score2[4];
????document.write(a+"<br>")
????sum=sum+parseInt(a);????
??}
?
??sum=Math.round(sum/10);
??document.write(sum);
?
</script>
</head>
<body>
</body>
</html>
2015-07-18
樓上正解,因為你只聲明額sum,但是未設置初始值,默認為undefined,undefined/10是nan,math.floor后,還是nan.
2015-07-18
給sum一個初始值0即可。