數組內的數組在 javascript 中得到 object

Question

你好朋友我有下面的數組，我想得到顯示名稱有迪拜的區域數組項我嘗試使用下面的代碼但不工作

 this.props = { countryListData: [ { "country": { "countryCode": "AE", "displayName": "United Arab Emirates", "repositoryId": "AE" }, "regions": [ { "regionCode": "AE-FU", "displayName": "Fujairah", "repositoryId": "AE-FU", "abbreviation": "FU" }, { "regionCode": "AE-DU", "displayName": "Dubai", "repositoryId": "AE-DU", "abbreviation": "DU" }, { "regionCode": "AE-UQ", "displayName": "Umm al-Quwain", "repositoryId": "AE-UQ", "abbreviation": "UQ" }, { "regionCode": "AE-AJ", "displayName": "Ajman", "repositoryId": "AE-AJ", "abbreviation": "AJ" }, { "regionCode": "AE-AZ", "displayName": "Abu Dhabi", "repositoryId": "AE-AZ", "abbreviation": "AZ" }, { "regionCode": "AE-RK", "displayName": "Ras al-Khaimah", "repositoryId": "AE-RK", "abbreviation": "RK" }, { "regionCode": "AE-SH", "displayName": "Sharjah", "repositoryId": "AE-SH", "abbreviation": "SH" } ], "repositoryId": "100003" } ] }; for (let index = 0; index < this.props.countryListData.length; index++) { for (let j = 0; j < this.props.countryListData[index].regions.length; j++) { console.log("Region Name --->", this.props.countryListData[index].regions[j].displayName); } }

我收到錯誤，例如區域未定義任何人幫助我如何獲得

Answer 1

您可以使用Array.prototype.find來做到這一點：

 const list = [ { "country": { "countryCode": "AE", "displayName": "United Arab Emirates", "repositoryId": "AE" }, "regions": [ { "regionCode": "AE-FU", "displayName": "Fujairah", "repositoryId": "AE-FU", "abbreviation": "FU" }, { "regionCode": "AE-DU", "displayName": "Dubai", "repositoryId": "AE-DU", "abbreviation": "DU" }, { "regionCode": "AE-UQ", "displayName": "Umm al-Quwain", "repositoryId": "AE-UQ", "abbreviation": "UQ" }, { "regionCode": "AE-AJ", "displayName": "Ajman", "repositoryId": "AE-AJ", "abbreviation": "AJ" }, { "regionCode": "AE-AZ", "displayName": "Abu Dhabi", "repositoryId": "AE-AZ", "abbreviation": "AZ" }, { "regionCode": "AE-RK", "displayName": "Ras al-Khaimah", "repositoryId": "AE-RK", "abbreviation": "RK" }, { "regionCode": "AE-SH", "displayName": "Sharjah", "repositoryId": "AE-SH", "abbreviation": "SH" } ], "repositoryId": "100003" } ]; console.log(list[0].regions.find(r => r.displayName === "Dubai"));

外部數組容器有原因嗎？ 考慮到數據結構，這似乎是多余的。

Answer 2

您可以使用以下 function 鏈：

this.props = {
  countryListData: [
    {
      "country": {
        "countryCode": "AE",
        "displayName": "United Arab Emirates",
        "repositoryId": "AE"
      },
      "regions": [
        {
          "regionCode": "AE-FU",
          "displayName": "Fujairah",
          "repositoryId": "AE-FU",
          "abbreviation": "FU"
        },
        {
          "regionCode": "AE-DU",
          "displayName": "Dubai",
          "repositoryId": "AE-DU",
          "abbreviation": "DU"
        },
        {
          "regionCode": "AE-UQ",
          "displayName": "Umm al-Quwain",
          "repositoryId": "AE-UQ",
          "abbreviation": "UQ"
        },
        {
          "regionCode": "AE-AJ",
          "displayName": "Ajman",
          "repositoryId": "AE-AJ",
          "abbreviation": "AJ"
        },
        {
          "regionCode": "AE-AZ",
          "displayName": "Abu Dhabi",
          "repositoryId": "AE-AZ",
          "abbreviation": "AZ"
        },
        {
          "regionCode": "AE-RK",
          "displayName": "Ras al-Khaimah",
          "repositoryId": "AE-RK",
          "abbreviation": "RK"
        },
        {
          "regionCode": "AE-SH",
          "displayName": "Sharjah",
          "repositoryId": "AE-SH",
          "abbreviation": "SH"
        }
      ],
      "repositoryId": "100003"
    }
  ]
};

this.props.countryListData.map(c => c.regions.filter((r)=> r.displayName === 'Dubai')).flat()[0]

Answer 3

您可以使用映射來獲取顯示名稱具有“迪拜”的區域數組項

        this.props.countryListData.map((it) =>
            it.regions.map((Arr) => {
              if (Arr.displayName === "Dubai"){
                 console.log(Arr);
                } 
             })
          )