根據父過濾器返回 Javascript 子數組

Question

免責聲明：我知道一些 Java 但幾乎沒有關於 Javascript 並且有大約 2 天的時間來解決別人的問題，其中這是一小部分。

我有一個嵌套數組。 我知道商店編號，但只需要獲取該商店中的零件數組。

"shops": [
    {
      "shopID": "15231",
      "city": "Anytown",
      "state": "MO",
      "inventory": [
        {
          "description": "filter",
          "partnumber": "MGL57047",
          "shelf": "Z",
        },
        {
          "description": "filter",
          "partnumber": "84060",
          "shelf": "A",
        }
    },
    {
      "shopID": "15232",
      "city": "Springfield",
      "state": "IL",
      "inventory": [
        {
          "description": "filter",
          "partnumber": "MGL57048",
          "shelf": "B",
        },
        {
          "description": "filter",
          "partnumber": "84061",
          "shelf": "A",
        }
    }

這是我嘗試過的：

const enteredShopID = '15231' // This isn't hard-coded in my app.
// Pull the list of all consumables for the current shop
var currentShop = application.data.shops.filter(s => s.shopID == enteredShopID)

這為我提供了一個包含商店和該商店所有庫存的數組，但我需要一個庫存數組。 我試過了

var currentShop = application.data.shops.inventory.filter(s => s.shopID == enteredShopID)

但這沒有用。 真的，我只是在這里摸索。 有沒有辦法使后一個語句起作用，並以某種方式引用父級的 shopID？

Answer 1

只需在過濾器后使用map()即可。

var currentShop = application.data.shops
   .filter(s => s.shopID == enteredShopID)[0]

// checking if the current shop is actually null because no shops matched the ID
var currentShopInventory = (currentShop || {}).inventory || []

或使用find()

// Note: If you use find(), there's a chance that there is no matching object
// So you'll have to check for that before you access the "inventory" key
// Otherwise you'll get "Cannot access 'inventory' of null"
var matchingShop = application.data.shops
   .find(s => s.shopID == enteredShopID)

// Doing the checking here using an "or" if the matchingShop is null
var currentShop = matchingShop || {}
var currentShopInventory = currentShop.inventory || []