将包含空数组的对象映射为属性会忽略整个对象

如何解决将包含空数组的对象映射为属性会忽略整个对象

我有一个对象数组-

let initialArr = [
  {
    "id": 1,"name": "product name","product_details": [
      {
        "id": 1,"details": "some details"
      }
    ],"subscriptions": [
      {
        "id": 1,"subs": "7 days"
      },{
        "id": 2,"subs": "15 days"
      }
    ]
  },{
    "id": 2,"name": "product name 2","product_details": [
      {
        "id": 2,"details": "some details 2"
      }
    ],{
    "id": 3,"name": "product name 3","product_details": [
      {
        "id": 3,"details": "some details 3"
      }
    ],"subscriptions": []
  }
]

这是我要实现的目标-

[
  {
    "id": 1,"detailsId" : 1,"details": "some details"
    "subsId": 1,"subs": "7 days"
  },{
    "id": 1,"details": "some details"
    "subsId": 2,"subs": "15 days"
  },"detailsId" : 2,"details": "some details 2"
    "subsId": 1,"details": "some details 2"
    "subsId": 2,"detailsId" : 3,"details": "some details 3"
  }
]

这就是我所做的-

initialArr.map(e => {
  e.product_details.map(p =>{
   e.subscriptions.map(s => {
      newArr.push({
        id: e.id,name: e.name,detailsId: p.id,details: p.details,subsId: s.id,subs:s.subs        
      }); 
   }); 
  })
})

如果subscriptions数组不为空，则此方法有效。如果对于某些产品，预订数组为空，则该产品不推入该数组。我无法找出解决方法。

第三个产品未推送到新阵列中。这就是我得到的-

[
  {
    "id": 1,"subs": "15 days"
  }
]

注意：尽管同一产品在新阵列中重复两次，但这是必需的-根据订阅阵列的“ subs”属性的产品。

假设我有更多的数组例如除了“订阅”之外，还有“定制”，“订单”等，而且我还希望推送这些数组的数据，这是对多个数组进行处理的正确方法吗？

解决方法

假设数组product_details始终具有1个元素，这是一种解决方案。
使用Array#reduce累积新的结果数组。用所有数据创建一个新的临时对象foreach元素。如果subscriptions数组为空，则将此临时对象推送到您的累积结果数组。否则，请使用Array#forEach遍历您的订阅。对于每个订阅，请使用Object.assign来复制您的临时对象。将订阅数据添加到此，并将其推送到结果数组。

const initialArr = [{ id: 1,name: "product name",product_details: [{ id: 1,details: "some details" }],subscriptions: [{ id: 1,subs: "7 days" },{ id: 2,subs: "15 days" }] },name: "product name 2",product_details: [{ id: 2,details: "some details 2" }],{ id: 3,name: "product name 3",product_details: [{ id: 3,details: "some details 3" }],subscriptions: [] }];

let res = initialArr.reduce((acc,cur) => {
    let temp = {
        id: cur.id,name: cur.name,detailsId: cur.product_details[0].id,details: cur.product_details[0].details
    }
    if (!cur.subscriptions.length)
        acc.push(temp);
    else {
        cur.subscriptions.forEach(subs => {
            let tempSub = Object.assign({},temp);
            tempSub.subsId = subs.id;
            tempSub.subs = subs.subs;
            acc.push(tempSub);
        })
    }
    return acc;
},[]);

console.log(res);

这里没有reduce，而是forEach的版本：

const initialArr = [{ id: 1,subscriptions: [] }];

let acc = [];
initialArr.forEach(cur => {
    let temp = {
        id: cur.id,temp);
            tempSub.subsId = subs.id;
            tempSub.subs = subs.subs;
            acc.push(tempSub);
        })
    }
});

console.log(acc);

,

您可以检查subscription的长度并返回一个对象而不是映射数组。

const
    data = [{ id: 1,subscriptions: [] }],result = data.flatMap(({ product_details: [{ id: detailsId,details }],subscriptions,...o }) => subscriptions.length
        ? subscriptions.map(({ id: subsId,subs }) => ({ ...o,detailsId,details,subsId,subs }))
        : ({ ...o,details })
    );

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

,

您需要明确处理此案：

if (e.subscriptions.length === 0) {
  newArr.push({ ... }
} else {
  e.subscriptions.map(...)
}

您还应该使用forEach而不是map。