如何计算JSON值的平均值并使用Javascript迭代这x次呢？

Question

我有一个JSON数据集，如下所示：

 {
   name: "Evelyn",
   assignment: "SCRUM",
   difficulty: 3,
   fun: 4
 }

等。

我试图计算每个作业的难度和乐趣值的平均值。因为我有10组/个人有56份作业，所以我的想法是先过滤这些作业，它应该产生56组作业，每一次的乐趣和难度都有10个值，然后计算每个作业的平均值。

我很难将这个计划付诸实施，因为我不知道如何体面地使这个新的JSON数据集/数组。我正在考虑地图，减少等，但只是挣扎着把它付诸行动。有什么简单的方法吗？

Answer 1

您可以使用Array.reduce()按赋值对数据进行分组。

一旦我们对数据进行分组，我们就可以得到difficulty和fun的平均值。

​

let data = [{ name: "Evelyn", assignment: "SCRUM", difficulty: 3, fun: 4 }, { name: "Bill", assignment: "SCRUM", difficulty: 1, fun: 3 }, { name: "Carol", assignment: "SCRUM", difficulty: 2, fun: 5 }, { name: "Evelyn", assignment: "PLANNING", difficulty: 5, fun: 3 }, { name: "Bill", assignment: "PLANNING", difficulty: 6, fun: 1 }, { name: "Carol", assignment: "PLANNING", difficulty: 1, fun: 2 } ]
 
const groupedData = Object.values(data.reduce((acc, { name, assignment, difficulty, fun }) => { 
     acc[assignment] = acc[assignment] || { assignment, difficulty: 0, fun: 0, participants: 0 };
     acc[assignment].difficulty += difficulty;
     acc[assignment].fun += fun;
     acc[assignment].participants++;
     return acc;
}, {}))

const result = groupedData.map(({ assignment, participants, difficulty, fun }) => { 
    return { 
        assignment,
        participants,
        averageDifficulty: difficulty / participants,
        averageFun: fun / participants
    }
});
 
console.log(result)

.as-console-wrapper { max-height: 100% !important; }

​