javascript - 使用普通 JavaScript 访问嵌套在 JSON 对象中的已知名称的属性值

Question

感谢您花时间阅读我的问题!我是 JavaScript 新手，一直无法找到以下问题的解决方案:

如何访问嵌套在名称动态更改的属性下的 JSON 对象中的属性值？

JSON 对象:

{
  "batchcomplete": "",
  "query": {
    "normalized": [
      {
        "from": "Theodore_Rubin",
        "to": "Theodore Rubin"
      }
    ],
    "pages": {
      "11820415": {
        "pageid": 11820415,
        "ns": 0,
        "title": "Theodore Rubin",
        "contentmodel": "wikitext",
        "pagelanguage": "en",
        "pagelanguagehtmlcode": "en",
        "pagelanguagedir": "ltr",
        "touched": "2016-02-12T17:34:52Z",
        "lastrevid": 138813300,
        "length": 34,
        "redirect": "",
        "new": "",
        "fullurl": "https://en.wikipedia.org/wiki/Theodore_Rubin",
        "editurl": "https://en.wikipedia.org/w/index.php?title=Theodore_Rubin&action=edit",
        "canonicalurl": "https://en.wikipedia.org/wiki/Theodore_Rubin"
      }
    }
  }
}

我正在尝试将属性 fullurl 的值分配给一个变量。据我了解，我可以使用括号和点符号的组合来访问 fullurl，例如 query.pages["2123909"].fullurl。问题在于属性名称 ["2123909"] 随着每个 JSON 请求的变化而变化。

如何在不知道嵌套属性名称的情况下访问 fullurl 属性的值？

非常感谢您的帮助!

Answer 1

如果只有一个键，则可以使用 Object.keys 获取第一个元素data.query.pages。

var data = {
        "batchcomplete": "",
        "query": {
            "normalized": [
              {
                  "from": "Theodore_Rubin",
                  "to": "Theodore Rubin"
              }
            ],
            "pages": {
                "11820415": {
                    "pageid": 11820415,
                    "ns": 0,
                    "title": "Theodore Rubin",
                    "contentmodel": "wikitext",
                    "pagelanguage": "en",
                    "pagelanguagehtmlcode": "en",
                    "pagelanguagedir": "ltr",
                    "touched": "2016-02-12T17:34:52Z",
                    "lastrevid": 138813300,
                    "length": 34,
                    "redirect": "",
                    "new": "",
                    "fullurl": "https://en.wikipedia.org/wiki/Theodore_Rubin",
                    "editurl": "https://en.wikipedia.org/w/index.php?title=Theodore_Rubin&action=edit",
                    "canonicalurl": "https://en.wikipedia.org/wiki/Theodore_Rubin"
                }
            }
        }
    };

console.log(data.query.pages[Object.keys(data.query.pages)[0]].fullurl);