计算数组（内部元素为对象）某个key值出现的次数

// 判断元素重复次数
    arrCheck(data, key) {
      let arr = JSON.parse(JSON.stringify(data));
      var newArr = [];
      let obj = {};
      for (var i = 0; i < arr.length; i++) {
        var temp = arr[i][key];
        var count = 0;
        for (var j = 0; j < arr.length; j++) {
          if (arr[j][key] == temp) {
            count++;
            arr[j][key] = -1;
          }
        }
        if (temp != -1) {
          obj[temp] = count;
        }
      }
      return obj;
    },