如何根据 OBJECTID 找出两个嵌套对象数组的差异？

Question

我正在努力寻找此代码的答案。我知道如何使用字符串/数字过滤数组，但是如何根据 OBJECTID 过滤嵌套的对象数组？ （抱歉，这是一个与我正在做的事情更相关的例子）

let geojson = [
  {properties: {OBJECTID: 6249646, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}}, 
  {properties: {OBJECTID: 6249646, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}}, 
  {properties: {OBJECTID: 6249647, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
  {properties: {OBJECTID: 6249647, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
  {properties: {OBJECTID: 6249648, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
  {properties: {OBJECTID: 6249649, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}} 
  ]


let newjson = [
  {properties: {OBJECTID: 6249647, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
  {properties: {OBJECTID: 6249648, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
  {properties: {OBJECTID: 6249649, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
  {properties: {OBJECTID: 6249650, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
  {properties: {OBJECTID: 6249651, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}}
  ]

What I want: [
    {properties: {OBJECTID: 6249650, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}},
    {properties: {OBJECTID: 6249651, FeatureCode: 10185, Version: 3, VersionDate: "1/25/2018"}}
  ]

这只是我实际拥有的代码的一个较小的“示例”。我尝试了一个 for 循环，并检查了 OBJECTID，但由于无限循环，页面刚刚崩溃。请问有人可以帮忙吗？

Answer 1

geojson.filter( obj => obj.properties.ID == 1 || obj.properties.ID == 2)

为什么不使用过滤器？

说明： 您可以只返回 true 或 false 来告诉过滤器方法是否符合您的条件。 filter 方法将调用您的内部函数并将数组的每个元素作为参数传递。

如果你有一个更大的数组，你可以这样做：

fil=[1,2,4];
geojson.filter( obj => fil.indexOf(obj.properties.ID) !== -1)

Answer 2

试试下面的代码，也许它会给你一个想法。但我不确定为什么它没有按预期工作

let geojson = [{properties: {ID: 1}, name: "Jimmy"}, 
               {properties: {ID: 2}, name: "Joe"}, 
               {properties: {ID: 3}, name: "Ji"}, 
               {properties: {ID: 4}, name: "my"}]


let test = [{properties: {ID: 3}, name: "Ji"}, {properties: {ID: 4}, name: "my"}]

var mappedTestArray = test.map(testObject => {
    return testObject.properties
})

console.log(mappedTestArray)

let geoJson = geojson.filter(geoObject => {
    console.log(geoObject.properties)
    console.log(mappedTestArray.includes(geoObject.properties))
   return mappedTestArray.some(el => el === geoObject.properties)
})

console.log(geoJson)

Answer 3

如果您需要通过多个值在数组中查找对象，这是一个简单的解决方案

const neededIDs = [1,2,3, ...];

const neededObjects = geojson.filter(item => neededIDs.includes(item.properties.ID));

Answer 4

1) 将ids 收集到需要过滤的test_ids 数组中
2）对geojson数组使用过滤器，检查是否不包含在上面的数组中。

let geojson = [
  { properties: { ID: 1 }, name: "Jimmy" },
  { properties: { ID: 2 }, name: "Joe" },
  { properties: { ID: 3 }, name: "Ji" },
  { properties: { ID: 4 }, name: "my" }
];

let test = [
  { properties: { ID: 3 }, name: "Ji" },
  { properties: { ID: 4 }, name: "my" }
];

const test_ids = test.map(x => x.properties.ID);

const res = geojson.filter(gj => !test_ids.includes(gj.properties.ID));

console.log(res);