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";

  score = score.join(":");

  score = score.split(":");

  var sumscore=0;

  for(var i = 0;i<score.length;i++){

      if(i%2 == 1){

          sumscore += parseInt(score[i]);

      }

  }