向 javascript 中的对象添加新值

Question

我有以下数组

array = [{
 key: '2001',
 values: [
  { id : '123a', points: 3, hours: 3 },
  { id : '123a', points: 4, hours: 2 },
  { id : '4444', points: 3, hours: 2 },
  { id : '4444', points: 3, hours: 5 },
]
}, {
 key: '2002',
 values: [
 { id : '12d3a', points: 5, hours: 2 },
 { id : '12w3a', points: 3, hours: 3 },
]
}]

有了这个功能

const {map, evolve, pipe, groupBy, prop, pluck, sum, toPairs, zipObj} = R;

const a = map(evolve({
        values: pipe(
            groupBy(prop('id')),
            map(pluck('hours')),
            map(sum),
            toPairs,
            map(zipObj(['id', 'hours']))
        )
    }))

我为每个键（2001、2002..）的每个 ID 收集了所有 "hours"

array = [{
 key: '2001',
 values: [
  { id : '123a', hours: 5 },
  { id : '4444',  hours: 7 }....

现在我想为每个对象添加另一个值，称为 sum。 var sum = (points*hours)/(sum(hours)).

知道我该怎么做吗？我试过更改 const a 但没有用，我不知道 ramda 是否可以执行此操作。也许另一种选择？

array = [{
 key: '2001',
 values: [
  { id : '123a', hours: 5, sum: 3.4 },
  { id : '4444',  hours: 7, sum: 3 }....

Answer 1

尝试关注

var array = [{
 key: '2001',
 values: [
  { id : '123a', points: 3, hours: 3 },
  { id : '123a', points: 4, hours: 2 },
  { id : '4444', points: 3, hours: 2 },
  { id : '4444', points: 3, hours: 5 },
]
}, {
 key: '2002',
 values: [
 { id : '12d3a', points: 5, hours: 2 },
 { id : '12w3a', points: 3, hours: 3 },
]
}];

array.forEach((item) => {
  var map = {};
  item.values.forEach((obj) => {
    map[obj.id] = map[obj.id] || [];
    map[obj.id].push(obj);
  });
  var values = [];
  Object.values(map).forEach((vals) => {
    var n = 0, d = 0;
    vals.forEach((val) => {
      n += val.points * val.hours;
      d += val.hours;
    });
    values.push({
      'id' : vals[0].id,
      'hours' : d,
      'sum' : n/d
    });
  });
  item.values = values;
});


console.log(array);

你也可以试试下面的逻辑

array.forEach((item) => {
  var map = {};
  item.values.forEach((obj) => {
    map[obj.id] = map[obj.id] || {id : obj.id, n: 0, hours: 0};
    map[obj.id].hours += obj.hours;
    map[obj.id].n += (obj.points * obj.hours);
  });
  var values = Object.values(map);
  values.forEach((val) => {
    val.sum = val.n / val.hours;
    delete val.n;
  });
  item.values = values;
});

Answer 2

这是一个 Ramda 版本，它通过简化为具有 ID、总小时数和总分的中间结构，然后转换为您的最终格式来工作：

const {map, evolve, pipe, groupBy, prop, reduce, values} = R;

const array = [{"key": "2001", "values": [{"hours": 3, "id": "123a", "points": 3}, {"hours": 2, "id": "123a", "points": 4}, {"hours": 2, "id": "4444", "points": 3}, {"hours": 5, "id": "4444", "points": 3}]}, {"key": "2002", "values": [{"hours": 2, "id": "12d3a", "points": 5}, {"hours": 3, "id": "12w3a", "points": 3}]}]

const a = map(evolve({
  values: pipe(
    groupBy(prop('id')),
    map(reduce(
      ({tp, th}, {id, points, hours}) => ({id, tp: tp + points * hours, th: th + hours})
      , {tp: 0, th: 0}
    )),
    values,
    map(({id, th, tp}) => ({id, hours: th, sum: tp/th})),
  )
}))

console.log(a(array))

<script src="//cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.js"></script>

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