如何使用基于 id 的分组数据从另一个数组创建一个数组？答案

【问题标题】：How to make a array from another array with grouping data based on id .?如何使用基于 id 的分组数据从另一个数组创建一个数组？
【发布时间】：2021-07-02 15:52:31
【问题描述】：

我有一个数组对象如下，

const data = [
   {
      "order_id":"ORDCUTHIUJ",
      "branch_code":"MVPA",
      "total_amt":199500,
      "product_details":[
         {
            "image":"CC252.jpg",
            "cate":"Mobile Accessories"
         }
      ]
   },
   {
      "order_id":"ORHOGFD79L",
      "branch_code":"PBVR",
      "total_amt":325880,
      "product_details":[
         {
            "image":"1617382086515.jpg",
            "cate":"Mobile Accessories"
         },
         {
            "image":"1617382322759.jpg",
            "cate":"Mobile Accessories"
         },
         {
            "image":"CC251.jpg",
            "cate":"Mobile Accessories"
         }
      ]
   },
   {
      "order_id":"ORIYDJLYSJ",
      "branch_code":"MVPA",
      "total_amt":1549500,
      "product_details":[
         {
            "image":"CC250.jpg",
            "cate":"Mobile Accessories"
         },
         {
            "image":"CC256.jpg",
            "cate":"Mobile Accessories"
         }
      ]
   }
]

我想要实现的是基于此构建一个新的数组，但我想将具有相同分支代码的数据分组到一个对象下。

预期输出：

const newData = 
[
  {
    MVPA: [
      {
        order_id: 'ORIYDJLYSJ',
        (otherdetails)
      },
      {
        order_id: 'ORDCUTHIUJ',
        (otherdetails
      }
    ]
  },
  PBVR: [
    {
      order_id: 'ORHOGFD79L',
      (otherdetails)
    }
  ]

有人可以帮我解决这个问题吗？我想要一个通用的解决方案，因为当我从 DB 获取时，这些数据可能比这更长。

【问题讨论】：

标签： javascript arrays typescript express

【解决方案1】：

您可以使用 Array.reduce 来做到这一点。

data.reduce((o, a) => (o[a.branch_code] = [ ...(o[a.branch_code] || []), a], o), {})

【讨论】：

【解决方案2】：

首先创建一个使用 branch_code 收集数据的对象。

const obj = data.reduce((map,obj)=>{
     if(obj.branch_code in map){
       map[obj.branch_code].push({...obj})
     }
     else{
      map[obj.branch_code]=[{...obj}]
     }
    return map
},{})

这给了

{MVPA: Array(2), PBVR: Array(1)}

然后，映射上述对象的键以创建所需的数组。

const result = Object.keys(obj).map(key => ({[key]:
[...obj[key]]}))

console.log('result',result)

这给了

(2) [{…}, {…}]
0: {MVPA: Array(2)}
1: {PBVR: Array(1)}

【讨论】：

【解决方案3】：

const uniqueBranchCode = [...new Set(data.map(i => i.branch_code))] // Get unique branch_code

const newData = uniqueBranchCode
.map(order => data.filter(orderSpecific => orderSpecific.branch_code === order)) // Filter to group together by branch_code
.map(item => ({[item[0].branch_code]: item})) // Assign key and return elements

const data = [
   {
      "order_id":"ORDCUTHIUJ",
      "branch_code":"MVPA",
      "total_amt":199500,
      "product_details":[
         {
            "image":"CC252.jpg",
            "cate":"Mobile Accessories"
         }
      ]
   },
   {
      "order_id":"ORHOGFD79L",
      "branch_code":"PBVR",
      "total_amt":325880,
      "product_details":[
         {
            "image":"1617382086515.jpg",
            "cate":"Mobile Accessories"
         },
         {
            "image":"1617382322759.jpg",
            "cate":"Mobile Accessories"
         },
         {
            "image":"CC251.jpg",
            "cate":"Mobile Accessories"
         }
      ]
   },
   {
      "order_id":"ORIYDJLYSJ",
      "branch_code":"MVPA",
      "total_amt":1549500,
      "product_details":[
         {
            "image":"CC250.jpg",
            "cate":"Mobile Accessories"
         },
         {
            "image":"CC256.jpg",
            "cate":"Mobile Accessories"
         }
      ]
   }
]

const uniqueBranchCode = [...new Set(data.map(i => i.branch_code))]

const newData = uniqueBranchCode
.map(order => data.filter(orderSpecific => orderSpecific.branch_code === order))
.map(item => ({[item[0].branch_code]: item}))

console.log(newData)

【讨论】：

【解决方案4】：

你可以试试这个方法

const data =[{"order_id":"ORDCUTHIUJ","branch_code":"MVPA","total_amt":199500,"product_details":[{"image":"CC252.jpg","cate":"Mobile Accessories"}]},{"order_id":"ORHOGFD79L","branch_code":"PBVR","total_amt":325880,"product_details":[{"image":"1617382086515.jpg","cate":"Mobile Accessories"},{"image":"1617382322759.jpg","cate":"Mobile Accessories"},{"image":"CC251.jpg","cate":"Mobile Accessories"}]},{"order_id":"ORIYDJLYSJ","branch_code":"MVPA","total_amt":1549500,"product_details":[{"image":"CC250.jpg","cate":"Mobile Accessories"},{"image":"CC256.jpg","cate":"Mobile Accessories"}]}];

const result = data.reduce((acc, {order_id, branch_code, product_details}) => {
  acc[branch_code] ??= {[branch_code]: []};
  acc[branch_code][branch_code].push({order_id, product_details});
  
  return acc;
}, {});

console.log(Object.values(result));

【讨论】：

这能回答你的问题吗？如果您需要任何帮助，请告诉我^^！ @Thorin

【解决方案5】：

let obj = {}

function comp(x) {
const f1 = data.filter(function (i) {
    return i.branch_code === x
})

return f1
}

for (let i = 0; i < data.length; i++) {
obj[`${data[i].branch_code}`] = comp(data[i].branch_code)
}

console.log(obj)

【讨论】：

在 for 循环中调用你的函数