如何使用另一个 json 的顺序对 json 个对象进行排序

Question

我有一个公园列表 (park_list) 可以按距离和面积排序。

我已经使用下面的代码成功地按距离排序：

sortList(index){
  return function(a, b){
    return (a[index] === b[index] ? 0 : (a[index] < b[index] ? -1 : 1));
  }
}

但是，按面积排序的问题与按距离排序的问题不同。我需要根据给定区域列表的顺序对区域进行排序 (area_list).

我的park_list是这样的：

[
    {
        "parkName" : "park4",
        "area_id" : "4"
    },
    {
        "parkName" : "park2",
        "area_id" : "2"
    },
    {
        "parkName" : "park1",
        "area_id" : "1"
    },
    {
        "parkName" : "park3",
        "area_id" : "3"
    },

]

我的area_list是这样的：

{
    "cityId": "1",
    "areaId": "1",
    "areaName": "area1"
}, {
    "cityId": "1",
    "areaId": "2",
    "areaName": "area2"
}, {
    "cityId": "1",
    "areaId": "3",
    "areaName": "area3"
}, {
    "cityId": "1",
    "areaId": "4",
    "areaName": "area4"
}

我需要根据 areaId 在 [= 中的顺序对 park_list 进行排序54=].

所以如果我的 area_list 是这样的：

{
    "cityId": "1",
    "areaId": "2",
    "areaName": "area2"
}, {
    "cityId": "1",
    "areaId": "4",
    "areaName": "area4"
}, {
    "cityId": "1",
    "areaId": "1",
    "areaName": "area1"
}, {
    "cityId": "1",
    "areaId": "3",
    "areaName": "area1"
}

我的park_list应该这样排序：

[
    {
        "parkName" : "park2",
        "area_id" : "2"
    },
    {
        "parkName" : "park4",
        "area_id" : "4"
    },
    {
        "parkName" : "park1",
        "area_id" : "1"
    },
    {
        "parkName" : "park3",
        "area_id" : "3"
    },

]

我真的很难过。如果能提供任何帮助，我将不胜感激。

Answer 1

使用Array#reduce方法创建一个保存每个area_id索引的对象，稍后使用该对象进行排序。

const area_list_index = area_list.reduce((obj, { areaId }, i) => {
  obj[areaId] = i;
  return obj;
}, {})


park_list.sort((a, b) => area_list_index[a.area_id] - area_list_index[b.area_id])

let park_list = [{
    "parkName": "park4",
    "area_id": "4"
  },
  {
    "parkName": "park2",
    "area_id": "2"
  },
  {
    "parkName": "park1",
    "area_id": "1"
  },
  {
    "parkName": "park3",
    "area_id": "3"
  },

]

let area_list = [{
  "cityId": "1",
  "areaId": "2",
  "areaName": "area2"
}, {
  "cityId": "1",
  "areaId": "4",
  "areaName": "area4"
}, {
  "cityId": "1",
  "areaId": "1",
  "areaName": "area1"
}, {
  "cityId": "1",
  "areaId": "3",
  "areaName": "area1"
}]

const area_list_index = area_list.reduce((obj, {
  areaId
}, i) => {
  obj[areaId] = i;
  return obj;
}, {})


park_list.sort((a, b) => area_list_index[a.area_id] - area_list_index[b.area_id])

console.log(park_list);

或者您可以使用 Array#findIndex 方法获取索引，但效率不高。

park_list.sort((a, b) => area_list.findIndex((o) => o.areaId == a.area_id) - area_list.findIndex((o) => o.areaId == b.area_id))

let park_list = [{
    "parkName": "park4",
    "area_id": "4"
  },
  {
    "parkName": "park2",
    "area_id": "2"
  },
  {
    "parkName": "park1",
    "area_id": "1"
  },
  {
    "parkName": "park3",
    "area_id": "3"
  },

]

let area_list = [{
  "cityId": "1",
  "areaId": "2",
  "areaName": "area2"
}, {
  "cityId": "1",
  "areaId": "4",
  "areaName": "area4"
}, {
  "cityId": "1",
  "areaId": "1",
  "areaName": "area1"
}, {
  "cityId": "1",
  "areaId": "3",
  "areaName": "area1"
}]



park_list.sort((a, b) => area_list.findIndex((o) => o.areaId == a.area_id) - area_list.findIndex((o) => o.areaId == b.area_id))

console.log(park_list);

Answer 2

您可以对想要的顺序取 Map 并按同一键的索引排序。

var park_list = [{ parkName: "park4", area_id: "4" }, { parkName: "park2", area_id: "2" }, { parkName: "park1", area_id: "1" }, { parkName: "park3", area_id: "3" }],
    area_list = [{ cityId: "1", areaId: "2", areaName: "area2" }, { cityId: "1", areaId: "4", areaName: "area4" }, { cityId: "1", areaId: "1", areaName: "area1" }, { cityId: "1", areaId: "3", areaName: "area1" }],
    order = new Map(area_list.map(({ areaId }, i) => [areaId, i]));
    
park_list.sort(({ area_id: a }, { area_id: b }) => order.get(a) - order.get(b));

console.log(park_list);

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如何使用另一个 json 的顺序对 json 个对象进行排序

How to sort json objects using the order of another json

javascript

arrays

json

ionic3

angular