相关疑难解决方法(0)

在数组中对对象进行分组的最有效方法是什么？

例如,给定此对象数组:

[ 
    { Phase: "Phase 1", Step: "Step 1", Task: "Task 1", Value: "5" },
    { Phase: "Phase 1", Step: "Step 1", Task: "Task 2", Value: "10" },
    { Phase: "Phase 1", Step: "Step 2", Task: "Task 1", Value: "15" },
    { Phase: "Phase 1", Step: "Step 2", Task: "Task 2", Value: "20" },
    { Phase: "Phase 2", Step: "Step 1", Task: "Task 1", Value: "25" },
    { Phase: "Phase 2", Step: "Step 1", Task: "Task 2", Value: "30" …

我正在研究一个问题,我必须将一个对象数组从一个表单分组到另一个表单.

一个例子优于1000字:

var initialData = [
  {
    house: { id: 1, text: "white" },
    room: { id: 1, text: "red" },
    price: 2.1
  },
  {
    house: { id: 1, text: "white" },
    room: { id: 2, text: "blue" },
    price: 3.1
  },
  {
    house: { id: 1, text: "white" },
    room: { id: 3, text: "red" },
    price: 5.8
  },
  {
    house: { id: 2, text: "black" },
    room: { id: 1, text: "yellow" },
    price: 9.1
  },
  {
    house: …

如果值不存在，需要将数组对象（arr1）的值推送到另一个数组对象（arr2）中。现有值不会推入另一个数组。

var arr1 = [{
    name: 'fred'
}, {
    name: 'bill'
}, {
    name: 'ted'
}, {
    name: 'james'
}];

var arr2 = [{
    name: 'spil'
}, {
    name: 'fred'
}, {
    name: 'bill'
},{
    name: 'paul'
}, {
    name: 'stone'
}];

function add(name) {
    var found = arr1.some(function (el) {
      return el.name === name;
    });
    if (!found) {
        arr1.push(arr2);
    }
    return arr2;
}

小提琴

如何通过对象键对对象数组进行分组，以根据分组创建新的对象数组？例如，我有一系列汽车对象：

const array = [
  {red: [ {height: 50} ]},
  {green: [ {height: 20} ]},
  {blue: [ {height: 30} ]},
  {blue: [ {height: 40} ]},
  {red: [ {height: 10} ]},
  {green: [ {height: 60} ]}
]

我想创建一个新的对象数组。（关键是颜色）

const result = [
  {red: [{height: 50}, {height: 10}]},
  {green: [{height: 20}, {height: 60}]},
  {blue: [{height: 30}, {height: 40}]}
]

我尝试使用 lodash.groupBy，但我根本不知道如何解决这个问题。

我的数组是这样的：

myArray = [
  {date: "2017-01-01", num: "2"}
  {date: "2017-01-02", num: "3"}
  {date: "2017-02-04", num: "6"}
  {date: "2017-02-05", num: "15"}
]

我想将其转换为：

myArray = [
   {group: "0", data: [
      {date: "2017-01-01", num: "2"}
      {date: "2017-01-02", num: "3"}]
   },
   {group: "1", data: [  
      {date: "2017-02-04", num: "6"}
      {date: "2017-02-05", num: "15"}]
   },
]

基本上，按月日期键分组。

I am trying to dynamically split an array of objects into groups based on values of a property.

Here is an example of the input:

`input = [
    {"name": "john", "location": "first"},
    {"name": "steve", "location": "first"},
    {"name": "paul", "location": "another"},
    {"name": "tony", "location": "random"},
    {"name": "ant", "location": "random"}
]`

and the desired output:

`solution(input, location) = [
    first:   [{"name": "john", "location": "first"},
              {"name": "steve", "location": "first"}],
    another: [{"name": "paul", "location": "another"}],
    random:  [{"name": "tony", "location": "random"},
              {"name": "ant", "location": "random"}] …

我有两个带有各种键/值的对象的 Javascript 数组。

我正在尝试使用从每个原始数组中选择的键/值来实现一个新的对象数组，但在特定键/值上具有唯一性。

例子：

const startDate = [
   {
    name: 'John', //Don't need this
    Id: 'ae570d88-809b-45b1-bc20-69b569e361ce', //This should be the 'unique' key
    datePosted: '2020-04-04T00:01:20.000Z' //This will be the start date
   }
]

const endDate = [
   {
    name: 'James', //Don't need this
    Id: 'ae570d88-809b-45b1-bc20-69b569e361ce', //This should be the 'unique' key
    datePosted: '2021-04-04T00:01:20.000Z' //This will be the end date
   }
]

const desiredOutput = [
    {
    'ae570d88-809b-45b1-bc20-69b569e361ce': { 
        startDate: '2020-04-04T00:01:20.000Z',
      endDate: '2021-04-04T00:01:20.000Z'
    }
  }
]

const desiredOutput2 = [
    { …

我收到带有对象的数据/数组.每个对象都有国家 - 城市和商店(在那个城市).

例如:

1. 美国 - 洛杉矶 - shop1
2. 意大利 - 米兰 - shop2

3. 意大利 - 罗马 - shopXY

   var data = [
     {country: "Italy", city: "Milan", shop: "shop123"},
     {country: "Italy", city: "Rome", shop: "shop2"},
     {country: "USA", city: "Los Angeles", shop: "shopXY"}
   ]
   

   Run Code Online (Sandbox Code Playgroud)

我有3列,我想只展示一次意大利,然后当我点击它时,我展示米兰和罗马,然后根据我是否点击罗马或米兰相应的商店.

以下是好的做法:

1. 获取所有数据,然后创建一个新的对象数组,所以我没有重复的国家,城市等.
2. 使用过滤方法 - 但是如何过滤它,如何检查重复项而不将它们存储在新数组中？
3. 还要别的吗？

我试图研究,但真的找不到任何东西,即使有人只是有一些提示,这将是伟大的,因为我完全失去了.谢谢!!!!

PS.我不想使用任何过滤器库,因为我自己尝试这样做.

var dictA = { male: 10, female: 20, unassigned: 30 };
var dictB = { male: 11, female: 21, unassigned: 31 };
var dictC = { male: 12, female: 22, unassigned: 32 };

有没有比多个循环更简单的方法来产生如下结果：

{
    male: [10, 11, 12],
    female: [20, 21, 22],
    unassigned: [30, 31, 32]
}

我不确定这里的“组合”是否正确。