javascript - 对对象数组中的两个值求和，然后插入到另一个对象数组中

Question

我有一个名为商店的对象数组:

stores = [
  {
    storeId: 1,
    city: "San Francisco",
    state: "CA",
  },
  {
    storeId: 2,
    city: "Seattle",
    state: "WA",
  },
  {
    storeId: 3,
    city: "Vancouver",
    state: "BC",
  },
  {
    storeId: 4,
    city: "Los Angeles",
    state: "CA",
  },
]

和另一个称为项目的对象数组:

items = [
  {
    itemId: 1,
    cost: 10,
    price: 20,
    sold: false,
    _storeId: 1,
  },
  {
    itemId: 2,
    cost: 10,
    price: 20,
    sold: false,
    _storeId: 1,
  },
  {
    itemId: 3,
    cost: 5,
    price: 12,
    sold: true,
    _storeId: 2,
  },
  {
    itemId: 4,
    cost: 12,
    price: 20,
    sold: false,
    _storeId: 3,
  },
  {
    itemId: 5,
    cost: 2,
    price: 10,
    sold: false,
    _storeId: 4,
  },
  {
    itemId: 6,
    cost: 10,
    price: 50,
    sold: true,
    _storeId: 4,
  },
]

我想按商店汇总以下类别:

• 总成本
• 总价

然后按商店统计商品总数:

• 总计

然后统计商店销售的商品小计:

• 已售商品

所以我最终的存储数组看起来像这样:

storesUpdated = [
  {
    storeId: 1,
    city: "San Francisco",
    state: "CA",
    totalCost: 20,
    totalPrice: 40,
    countTotalItems: 2,
    countSoldItems: 0
  },
  {
    storeId: 2,
    city: "Seattle",
    state: "WA",
    totalCost: 5,
    totalPrice: 12,
    countTotalItems: 1,
    countSoldItems: 1
  },
  {
    storeId: 3,
    city: "Vancouver",
    state: "BC",
    totalCost: 12,
    totalPrice: 20,
    countTotalItems: 1,
    countSoldItems: 0
  },
  {
    storeId: 4,
    city: "Los Angeles",
    state: "CA",
    totalCost: 12,
    totalPrice: 60,
    countTotalItems: 2,
    countSoldItems: 1
  },
]

我试过映射 stores 数组但卡在了这里:

const storesUpdated = stores.map((store) => {
   = {}
  items.forEach(item => {
    if (item._storeId === store.storeId) {
      return totalCost {
        'storeId' : item.storeId,

      }
    }
  })
})

有什么想法吗？非常感谢。

Answer 1

const stores = [{storeId:1,city:"San Francisco",state:"CA",},{storeId:2,city:"Seattle",state:"WA",},{storeId:3,city:"Vancouver",state:"BC",},{storeId:4,city:"Los Angeles",state:"CA",},]
const items = [{itemId:1,cost:10,price:20,sold:!1,_storeId:1,},{itemId:2,cost:10,price:20,sold:!1,_storeId:1,},{itemId:3,cost:5,price:12,sold:!0,_storeId:2,},{itemId:4,cost:12,price:20,sold:!1,_storeId:3,},{itemId:5,cost:2,price:10,sold:!1,_storeId:4,},{itemId:6,cost:10,price:50,sold:!0,_storeId:4,},]

const storesUpdated = stores.map((store) => {
  const updatedStore = { ...store,
    totalCost: 0,
    totalPrice: 0,
    countTotalItems: 0,
    countSoldItems: 0
  }
  
  items.forEach(item => {
    if (item._storeId === store.storeId) {
      updatedStore.totalCost += item.cost
      updatedStore.totalPrice += item.price
      updatedStore.countTotalItems += 1
      updatedStore.countSoldItems += item.sold ? 1 : 0
    }
  })
  
  return updatedStore
})

console.log(storesUpdated)