摸索数组中的类似记录键？

编程问答 2022-08-15

问题描述

我下面有一个这样的数组

[
  {
    "Date": "2020-07","data": [
      {
        "id": "35ebd073-600c-4be4-a750-41c4be5ed24a","Date": "2020-07-03T00:00:00.000Z","transactionId": "13","transactionType": "Payment","amount": 1500
      }
    ]
  },{
    "Date": "2020-07","data": [
      {
        "id": "4e126519-e27b-4e82-bb81-689c7dc63c9b","Date": "2020-07-02T00:00:00.000Z","transactionId": "4","amount": 1000
      }
    ]
  },{
    "Date": "2020-06","data": [
      {
        "id": "646d6497-9dea-4f27-896e-a45d97a252ea","Date": "2020-06-04T00:00:00.000Z","transactionId": "14","data": [
      {
        "id": "cf44e27f-2111-462d-b3bd-420a193745b8","Date": "2020-06-02T00:00:00.000Z","transactionId": "5","amount": 1000
      }
    ]
  }
]

这里有键Date，并且同一日期键有两个值。现在我想如果Date是相同的，那么数据数组记录应该合并。

所以我希望输出为

[
  {
    "Date": "2020-07","amount": 1500
      },{
        "id": "4e126519-e27b-4e82-bb81-689c7dc63c9b",{
        "id": "cf44e27f-2111-462d-b3bd-420a193745b8","amount": 1000
      }
    ]
  }
]

请告诉我最佳的实现方式吗？

解决方法

您可以使用dictionary并轻松检查密钥是否已存在，然后追加新数据，否则您将日期添加为新密钥。

var dict = {};
if (!("xxxx-xx" in dict)){ //if the key is not the dict

    dict["xxxx-xx"] = [{       //we are storing an array because we want to add other later
         id: "....",transactionId: "..."
         //etc...
    }]
}

else {                           //if the key already exists,we push new data to the array
    dict["xxxx-xx"].push({       //you can use push because is an array of objects
         id: "....",transactionId: "..."
         //etc...
    })
}

我希望它会有所帮助。 array不太方便检查键是否已存在和避免重复（默认情况下为dict / object）。

,

arr =您的数据集

obj =这将是您的输出

arr.forEach((elem) => {
    if(obj[elem.Date]) {
       obj[elem.Date].data.push(elem.data);
    } else {
       obj[elem.Date] = {
       data: [elem.data]
    }
  }
});
,

首先，您必须按属性Date对对象数组进行分组。然后按[Date,groupsByDate]的键值对分组，然后从每个组中获取数据

const res = _.chain(data)
  .groupBy("Date")
  .toPairs()
  .map(([key,value]) => ({
    Date: key,data: _.flatMap(value,"data"),}))
  .value()

完整代码

const data = [
  {
    Date: "2020-07",data: [
      {
        id: "35ebd073-600c-4be4-a750-41c4be5ed24a",Date: "2020-07-03T00:00:00.000Z",transactionId: "13",transactionType: "Payment",amount: 1500,},],{
    Date: "2020-07",data: [
      {
        id: "4e126519-e27b-4e82-bb81-689c7dc63c9b",Date: "2020-07-02T00:00:00.000Z",transactionId: "4",amount: 1000,{
    Date: "2020-06",data: [
      {
        id: "646d6497-9dea-4f27-896e-a45d97a252ea",Date: "2020-06-04T00:00:00.000Z",transactionId: "14",data: [
      {
        id: "cf44e27f-2111-462d-b3bd-420a193745b8",Date: "2020-06-02T00:00:00.000Z",transactionId: "5",]

const res = _.chain(data)
  .groupBy("Date")
  .toPairs()
  .map(([key,}))
  .value()

console.log(JSON.stringify(res,null,2))
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