求和出来是76???
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 arr1=scoreStr.split(";");
document.write(arr1+"<br>");
for(var i=0;i<arr1.length;i++){
/*var arr2=arr1[i].indexOf(":");*/
var sum="";
sum+=parseInt(arr1[i].substring(3));
}
document.write(arr1.length+"<br>");
document.write(sum + "<br>");
var aver=parseInt(sum/arr1.length);