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javascript - 将对象数组压缩为具有嵌套数组的唯一对象数组

问题描述

我在 MongoDB 中有 arr 数据，需要将文档压缩为一个，以便可以在 chartjs 中显示数据。

arr = [
    {
        "_id": "5d7baef782e09dc7f6b5be2d",
        "awaySpread": "3.0",
        "homeSpread": "-3.0",
        "homeTeam": "Tennessee Titans",
        "awayId": "4529605_261_sp",
        "awayTeam": "Indianapolis Colts",
        "homeId": "4529605_262_sp",
        "eventDate": "2019-09-15 13:00:00",
        "createdDate": "2019-09-13T13:00:06.527Z"
    },
    {
        "_id": "5d7baef782e09dc7f6b5be31",
        "awaySpread": "-19.5",
        "homeSpread": "19.5",
        "homeTeam": "Miami Dolphins",
        "awayId": "4529609_269_sp",
        "awayTeam": "New England Patriots",
        "homeId": "4529609_270_sp",
        "eventDate": "2019-09-15 13:00:00",
        "createdDate": "2019-09-13T13:00:06.527Z"
    },
    {
        "_id": "5d7baef782e09dc7f6b5be2d",
        "awaySpread": "2.5",
        "homeSpread": "-2.5",
        "homeTeam": "Tennessee Titans",
        "awayId": "4529605_261_sp",
        "awayTeam": "Indianapolis Colts",
        "homeId": "4529605_262_sp",
        "eventDate": "2019-09-15 13:00:00",
        "createdDate": "2019-09-13T13:30:06.527Z"
    }
]

希望进入：

newarr = [
    {
        "_id": "5d7baef782e09dc7f6b5be2d",
        "awaySpread": "3.0",
        "homeSpread": "-3.0",
        "homeTeam": "Tennessee Titans",
        "awayId": "4529605_261_sp",
        "awayTeam": "Indianapolis Colts",
        "homeId": "4529605_262_sp",
        "eventDate": "2019-09-15 13:00:00",
        "createdDate": "2019-09-13T13:00:06.527Z",
        "lines": {
           "spread": ["3.0","2.5"],
           "dates: : ["2019-09-13T13:00:06.527Z","2019-09-13T13:30:06.527Z"]
         },

    },
    {
        "_id": "5d7baef782e09dc7f6b5be31",
        "awaySpread": "-19.5",
        "homeSpread": "19.5",
        "homeTeam": "Miami Dolphins",
        "awayId": "4529609_269_sp",
        "awayTeam": "New England Patriots",
        "homeId": "4529609_270_sp",
        "eventDate": "2019-09-15 13:00:00"
        "createdDate": "2019-09-13T13:00:06.527Z",
        "lines": {
           "spread": ["-19.5"],
           "dates: : ["2019-09-13T13:00:06.527Z"]
         },
    }
]

我可以使用过滤器仅返回基于 awayId 的唯一对象，但我不确定使用过滤器是否允许我推送带有点差和日期的行。

标签： javascriptarraysnode.jsmongodbchart.js

解决方案

我会使用reduce函数。

我正在构建一个对象，其中 id 是键，值是对象。当我已经有 id 时（我第二次遇到相同的 id），我推送相关值。

最后，我控制台记录了您想要的输出对象的值。

arr = [
    {
        "_id": "5d7baef782e09dc7f6b5be2d",
        "awaySpread": "3.0",
        "homeSpread": "-3.0",
        "homeTeam": "Tennessee Titans",
        "awayId": "4529605_261_sp",
        "awayTeam": "Indianapolis Colts",
        "homeId": "4529605_262_sp",
        "eventDate": "2019-09-15 13:00:00"
    },
    {
        "_id": "5d7baef782e09dc7f6b5be31",
        "awaySpread": "-19.5",
        "homeSpread": "19.5",
        "homeTeam": "Miami Dolphins",
        "awayId": "4529609_269_sp",
        "awayTeam": "New England Patriots",
        "homeId": "4529609_270_sp",
        "eventDate": "2019-09-15 13:00:00"
    },
    {
        "_id": "5d7baef782e09dc7f6b5be2d",
        "awaySpread": "2.5",
        "homeSpread": "-2.5",
        "homeTeam": "Tennessee Titans",
        "awayId": "4529605_261_sp",
        "awayTeam": "Indianapolis Colts",
        "homeId": "4529605_262_sp",
        "eventDate": "2019-09-15 13:00:00"
    }
]

const newArr = arr.reduce((result, itr) => {
  if (result[itr.awayId]) {
    result[itr.awayId].lines.spread.push(itr.awaySpread)
    result[itr.awayId].lines.dates.push(itr.eventDate)
  } else {
    result[itr.awayId] = { ...itr, lines: { spread: [itr.awaySpread], dates: [itr.eventDate] }}
  }
  return result
}, {})

console.log(Object.values(newArr))

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