如何在Node.js中过滤这个对象数组？

Question

我有一些数据看起来像这样-

[
   {
      "element": 1,
      "id": 1
   },
   {
      "element": 1,
      "id": 2
   },
   {
      "element": 2,
      "id": 1
   },
   {
      "element": 2,
      "id": 2
   },
   {
      "element": 3,
      "id": 1
   }
]

我有上面的数据，因为它是对象数组，我想主要在 Node.js 中按下面给出的方式进行过滤，我想用元素和 return 新数组进行过滤。如果我对此有任何解决方案，那将会很有帮助。

[
   {
      "element": 1,
      "data": [
         {
            "element": 1,
            "id": 1
         },
         {
            "element": 1,
            "id": 2
         }
      ]
   },
   {
      "element": 2,
      "data": [
         {
            "element": 2,
            "id": 1
         }
      ]
   },
   {
      "element": 3,
      "data": [
         {
            "element": 3,
            "id": 1
         }
      ]
   }
]

Answer 1

好的，让我们在中获取一些变量：

const elementsData = [{ element: 0001, id: 1 }, { element: 0001, id: 2 }, { element: 0001, id: 3 }, { element: 0001, id: 4 }, { element: 0002, id: 1 }, { element: 0002, id: 2 }, { element: 0002, id: 3 }, { element: 0003, id: 1 } ]

首先，您需要过滤掉唯一元素值：

const uniqueElements = []
elementsData.forEach(datum => {
   if (!uniqueElements.includes(datum.element)) {
      uniqueElements.push(datum.element)
   }
})

然后按 uniqueElement 进行分组

// loop through the unique Elements
const output = uniqueElements.map(uniqueElement => {
   // this will return the object with the specified fields
   return {
       // element value
       element: uniqueElement,

       // filter through elementsData for matching elements and save then into an array.
       // You can do sort() here if you want to sort them by id, but this is basically it
       data: elementsData.filter(elementData => elementsData.element === uniqueElement)
   }
})

如何在Node.js中过滤这个对象数组？

How to filter this array of object in Node.js?

arrays

reduce

filter

node.js