javascript - 基于字符串变量访问嵌套的javascript对象

Question

我正在尝试创建一个 javascript 对象，它可以让我轻松地检查某本书中有多少章以及某章中有多少节经文。

我的计划是为对象建立这样的结构:

const amounts = {
    book: {
        bookNumber: 1,
        bookChapters: 50,
        chapter:
        {
            chapterNumber: 1,
            versesInChapter: 31
        },

        chapter:
        {
            chapterNumber: 2,
            versesInChapter: 25
        }
    },

    book: {
        bookNumber: 2,
        bookChapters: 40,
        chapter:
        {
            chapterNumber: 1,
            versesInChapter: 26
        },

        chapter:
        {
            chapterNumber: 2,
            versesInChapter: 22
        }
    }

}

如何根据变量值访问这种结构的嵌套值？例如，我可能有一个 var bookNum = 2 和 var chapterNum = 2，我的目标是获取第 2 本书第 2 章中的经文数量。我将如何编写这样的查询？

编辑:根据评论，我的对象结构也很糟糕，所以我还要求指出正确的结构，使我能够有效地访问经文的数量。

Answer 1

您可以重写您的 var 金额，如下所示，这将有助于操作

const books = [
 {
        bookNumber: 1,
        bookChapters: 50,
        chapter:[
        {
            chapterNumber: 1,
            versesInChapter: 31
        },
        {
            chapterNumber: 2,
            versesInChapter: 25
        }
    ],
}

    {
        bookNumber: 2,
        bookChapters: 40,
        chapter:[
        {
            chapterNumber: 1,
            versesInChapter: 26
        },

        {
            chapterNumber: 2,
            versesInChapter: 22
        }
    ]
    }

]

const books = [{
    bookNumber: 1,
    bookChapters: 50,
    chapter: [{
        chapterNumber: 1,
        versesInChapter: 31
      },
      {
        chapterNumber: 2,
        versesInChapter: 25
      }
    ],
  },

  {
    bookNumber: 2,
    bookChapters: 40,
    chapter: [{
        chapterNumber: 1,
        versesInChapter: 26
      },

      {
        chapterNumber: 2,
        versesInChapter: 22
      }
    ]
  }

]

var serach = books.filter(function(book) {
  //console.log("books",book);
  return book.bookNumber == 1;
})[0];
console.log("Searched book!", serach)

//And for desired result you can use forEach and filter 
var num = 2,
  chap = 1,
  found_chapter;

books.forEach(function(book) {
  if (book.bookNumber == num) { //found the book
    console.log("found book", book);
    found_chapter = book.chapter.filter(function(chapter) {
      return chapter.chapterNumber == chap; //found chapter WRT found book
    })[0]

  }
});
console.log("found chapter-", found_chapter, "--found verse", found_chapter.versesInChapter)

正如上面的代码片段，您可以过滤掉您的搜索数据，并可以轻松地再次循环以找到所需的结果

希望对你有帮助!