将二维数组中的 ID 与另一个二维数组中的 ID 进行比较

Question

好的，这是按ID分组Javascript对象数组系列中的另一个，但是这一次，我们在数组对象(item3(中有一个ID数组，它将与另一个对象数组进行比较。

var existingArray = [
    {
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0200","0300"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0100","0300"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0100"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0300"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0200", "0100"],
      "item4": "blah4",
      "item5": "blah5"
    }
]

这是我们最喜欢的 DATA2 数组，它包含我们想要提取的信息(Candidate Name(，如果"relatedId"与 EXISTINGARRAY 中 item3 中的任何 ID 相同。

var data2 = [
    {"CandidateName": "Mary", "relatedId": ["0100", "0200"]},
    { "CandidateName": "John", "relatedId": ["0200"]},
    { "CandidateName":"Peter", "relatedId": ["0300", "0100"]},
    { "CandidateName": "Paul", "relatedId": ["0300"]}
];

所以这个想法是，如果data2[i].relatedId[j] === existingArray[k].item3[l]中的任何ID，提取"Candidate Name"并将其添加到EXISTINGARRAY中，这样我们最终会得到如下所示的内容。

existingArray = [
    {
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0200","0300"],
      "item4": "blah4",
      "item5": "blah5",
      "item6": ["Mary", "Jonh", "Peter", "Paul"]
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0100","0300"],
      "item4": "blah4",
      "item5": "blah5",
      "item6": ["Mary", "Peter", "Paul"]
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0100"],
      "item4": "blah4",
      "item5": "blah5",
      "item6": ["Mary", "Peter"]
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0300"],
      "item4": "blah4",
      "item5": "blah5",
      "item6": ["Peter", "Paul"]
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0200", "0100"],
      "item4": "blah4",
      "item5": "blah5",
      "item6": ["Mary", "John","Peter"]
    }
]

Answer 1

下面是一个 ES6 解决方案：

existingArray.forEach( function (obj) {
    obj.item6 = [...new Set(obj.item3.reduce( (acc, id) => acc.concat(this.get(id)), [] ))]
}, data2.reduce (
    (acc, obj) => obj.relatedId.reduce (
        (acc, id) => acc.set(id, (acc.get(id) || []).concat(obj.CandidateName)), acc
    ), new Map()
));

var existingArray = [
    {
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0200","0300"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0100","0300"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0100"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0300"],
      "item4": "blah4",
      "item5": "blah5"
    },{
      "item1": "Blah1",
      "item2": "blah2",
      "item3": ["0200", "0100"],
      "item4": "blah4",
      "item5": "blah5"
    }
]
var data2 = [
    {"CandidateName": "Mary", "relatedId": ["0100", "0200"]},
    { "CandidateName": "John", "relatedId": ["0200"]},
    { "CandidateName":"Peter", "relatedId": ["0300", "0100"]},
    { "CandidateName": "Paul", "relatedId": ["0300"]}
];
existingArray.forEach( function (obj) {
    obj.item6 = [...new Set(obj.item3.reduce( (acc, id) => acc.concat(this.get(id)), [] ))]
}, data2.reduce (
    (acc, obj) => obj.relatedId.reduce (
        (acc, id) => acc.set(id, (acc.get(id) || []).concat(obj.CandidateName)), acc
    ), new Map()
));
console.log(existingArray);

解释

代码真正从最后开始，创建一个空Map：

new Map()

这成为变量(名为 acc (，当 data2 迭代时reduce 累积数据：

data2.reduce

此reduce操作是嵌套的，以便单独迭代每个relatedId。如果累积值 ( acc ( 尚未包含找到的 id，则创建一个新数组：

acc.get(id) || []

。否则，将使用找到的数组值。将附加候选名称：

.concat(obj.CandidateName)

。这被放回acc键id：

acc.set(id, ...)

当 set 方法返回自身acc时，它与需要此返回值以便再次acc回调的下一次调用的reduce配合得很好。

外部reduce调用的结果是，这是一个由data2中找到的所有id值键控的Map，每个值都是关联名称的数组。

然后，此值作为第二个参数传递给forEach调用，从而成为 this 的值。所以当你看到：

this.get(id)

它正在从上述Map中检索id的候选名称数组。

在forEach回调中，进行了另一个reduce来迭代item3中的id值：

obj.item3.reduce

这会累积到一个名称数组中，然后将其传递给 Set 构造函数：

new Set(...)

这样做是为了从名称数组中删除重复项。此Set立即使用扩展运算符再次转换为数组：

[...new Set()]

因此，所有item6属性都获得了它们的价值。

Answer 2

您可以循环 existingArray 并使用 map() 添加 item6，要创建该数组，您可以首先使用 filter() 和 some() 来过滤 relatedId 中包含与现有数组中当前对象相同值的对象，然后仅使用 map() 仅返回名称和返回对象。

var existingArray = [{"item1":"Blah1","item2":"blah2","item3":["0200","0300"],"item4":"blah4","item5":"blah5"},{"item1":"Blah1","item2":"blah2","item3":["0100","0300"],"item4":"blah4","item5":"blah5"},{"item1":"Blah1","item2":"blah2","item3":["0100"],"item4":"blah4","item5":"blah5"},{"item1":"Blah1","item2":"blah2","item3":["0300"],"item4":"blah4","item5":"blah5"},{"item1":"Blah1","item2":"blah2","item3":["0200","0100"],"item4":"blah4","item5":"blah5"}];
var data2 = [{"CandidateName":"Mary","relatedId":["0100","0200"]},{"CandidateName":"John","relatedId":["0200"]},{"CandidateName":"Peter","relatedId":["0300","0100"]},{"CandidateName":"Paul","relatedId":["0300"]}];
var result = existingArray.map(function(o) {
  o.item6 = data2.filter(function(e) {
    return o.item3.some(function(a) {
      return e.relatedId.indexOf(a) != -1;
    })
  }).map(function(e) {
    return e.CandidateName;
  })
  return o;
})
console.log(result)