JavaScript 通过一个或两个键对对象数组进行分组和转换

Question

如何按 Date 分组并转换以下数据

// PROVIDED INPUT
[
  {
    "Date": "2021/Dec/01",
    "Media category": "Canvas",
    "Printed square meters": 244.58
  },
  {
    "Date": "2021/Dec/01",
    "Media category": "Film",
    "Printed square meters": 152.62
  },
  {
    "Date": "2021/Dec/01",
    "Media category": "Heavy paper > 200gsm",
    "Printed square meters": 256.02000000000004
  },
  {
    "Date": "2021/Dec/02",
    "Media category": "Textile",
    "Printed square meters": 144.95999999999998
  },
  {
    "Date": "2021/Dec/02",
    "Media category": "Thick film > 200 um",
    "Printed square meters": 153.37
  },
  {
    "Date": "2021/Dec/02",
    "Media category": "Paper",
    "Printed square meters": 217.2
  }, ...
]

与 JavaScript 合并。我尝试使用 Lodash 的 groupBy() 和 mergeWith() 来完成此操作，但我一无所获：

// DESIRED OUTPUT
[
  {
    "Date": "2021/Dec/01",
    "Canvas": 244.58,
    "Film": 152.62
    "Heavy paper > 200gsm": 256.02000000000004
  },
  {
    "Date": "2021/Dec/02",
    "Textile": 144.95999999999998,
    "Thick film > 200 um": 153.37
    "Paper": 217.2
  }, ...
]

此外，是否可以按两个键分组 - 即 Date 和 Printer id:

// PROVIDED INPUT
[
  {
    "Date": "2021/Dec/01",
    "Printer id": "700",
    "Media category": "Canvas",
    "Printed square meters": 244.58
  },
  {
    "Date": "2021/Dec/01",
    "Printer id": "700",
    "Media category": "Film",
    "Printed square meters": 152.62
  },
  {
    "Date": "2021/Dec/01",
    "Printer id": "701",
    "Media category": "Heavy paper > 200gsm",
    "Printed square meters": 256.02000000000004
  },
  {
    "Date": "2021/Dec/01",
    "Printer id": "701",
    "Media category": "Textile",
    "Printed square meters": 144.95999999999998
  }, ...
]

// DESIRED OUTPUT
[
  {
    "Date": "2021/Dec/01",
    "Printer id": "700",
    "Canvas": 244.58,
    "Film": 152.62
  },
  {
    "Date": "2021/Dec/01",
    "Printer id": "701",
    "Heavy paper > 200gsm": 256.02000000000004,
    "Textile": 144.95999999999998
  }, ...

我尝试用这段代码做第一个，但不知道如何转换字段：

// What I tried doing
console.log(_(data)
    .groupBy('Date')
    .map(g => _.mergeWith({}, ...g, (obj, src) =>
      _.isArray(obj) ? obj.concat(src) : undefined))
    .value());

在提交这个之前检查了很多问题，但是none 有字段的转换。

Answer 1

您可以在 Date 和 Printer id 上创建计算键并基于此键进行分组。

const data = [ { "Date": "2021/Dec/01", "Printer id": "700", "Media category": "Canvas", "Printed square meters": 244.58 }, { "Date": "2021/Dec/01", "Printer id": "700", "Media category": "Film", "Printed square meters": 152.62 }, { "Date": "2021/Dec/01", "Printer id": "701", "Media category": "Heavy paper > 200gsm", "Printed square meters": 256.02000000000004 }, { "Date": "2021/Dec/01", "Printer id": "701", "Media category": "Textile", "Printed square meters": 144.95999999999998 }],
      result = Object.values(data.reduce((r, o) => {
        let key = o.Date + '-' + o['Printer id'];
        r[key] ??= {Date: o.Date, 'Printer id': o['Printer id']};
        r[key][o['Media category']] = (r[key][o['Media category']] ?? 0) + o['Printed square meters'];
        return r;
      },{}));
console.log(result);

JavaScript 通过一个或两个键对对象数组进行分组和转换

JavaScript group and transform array of objects by one or two keys

javascript

arrays

json

lodash

transformation