小编Ran*_*l D的帖子

假设我有以下对象数组:

var arr = [
  {"name": "John", "score": "8.8"},
  {"name": "John", "score": "8.6"},
  {"name": "John", "score": "9.0"},
  {"name": "John", "score": "8.3"},
  {"name": "Tom",  "score": "7.9"}
];

var count = 0;
var avgScore = arr.reduce(function (sum,person) {
  if (person.name == "John") {
    count+=1;
    return sum + parseFloat(person.score);
  }
  return sum;
},0)/count);

问题:有没有办法在不创建全局计数变量的情况下计算"John"的平均分数.理想情况下,计数将在arr.reduce中的匿名函数内部.