Question

我有array of objects如下：

[
  {
    "__v": 0,
    "_id": "5634fa3df925a0ac02f1b0fa",
    "groupname": "group 1",
    "subgroups": [
      {
        "__v": 0,
        "_id": "5634fa63f925a0ac02f1b0fc",
        "subgroupname": "subgroup 1",
        "books": [
          {                
            "bookname": {
              "name": "sasasasasasP"
            }
         }
        ]
    ]
  },
  {
    "__v": 0,
    "_id": "5634fa3df925a0ac02f1b0fd",
    "groupname": "group 2",
    "subgroups": [
      {
        "__v": 0,
        "_id": "5634fa63f925a0ac02f1befc",
        "subgroupname": "subgroup 2",
        "books": [
          {                
            "bookname": {
              "name": "book 2"
            }
         }
        ]
    ]
  }
]

我想从上面的对象中形成如下所示的array of objects。

[
    {
        "groupname": "Group 1",
        "subgroupname": "subgroup 1",
        "bookname": "Enersol"
    },
    {
        "groupname": "Group 2",
        "subgroupname": "subgroup 2",
        "bookname": "Enersol"
    }
]

下面是我尝试过的，但是在第一个对象在数组内形成之后循环失败了。

var apiListData = [];
for (var i = 0, len = groups.length; i < len; i++) {
    for (var j = 0, len = groups[i].subgroups.length; j < len; j++) {
        for (var k = 0, len = groups[i].subgroups[j].books.length; k < len; k++) {
            apiListData.push({
                gname: groups[i].groupname,
                sname: groups.[i].subgroups[j].subgroupname,
                bookname: groups[i].subgroups[j].books[k].bookname
            })
        }
    }
}

Answer 1

请查看http://jsfiddle.net/es47k33o/

这里有很多错误：

你提供的JSON结构非常混乱，它固定在小提琴中
错字：sname: groups.[i].subgroups[j].subgroupname
要访问书名的字符串值，您必须获得比bookname: groups[i].subgroups[j].books[k].bookname
这里你的实际算法问题是你总是重新声明变量len。我根据各自的索引重命名了第二个和第三个：

＆＃13;

var apiListData = [];
for (var i = 0, len = groups.length; i < len; i++) {
	for (var j = 0, lenj = groups[i].subgroups.length; j < lenj; j++) {
		for (var k = 0, lenk = groups[i].subgroups[j].books.length; k < lenk; k++) {
			apiListData.push({
				gname: groups[i].groupname,
				sname: groups[i].subgroups[j].subgroupname,
				bookname: groups[i].subgroups[j].books[k].bookname.name
			})
		}
	}
}

＆＃13;

Answer 2

试试这个JSFiddle sample并查看浏览器控制台日志。

首先，您的JSON已损坏，每组中都缺少}，这是有效的：

var groups = [{
    "__v": 0,
        "_id": "5634fa3df925a0ac02f1b0fa",
        "groupname": "group 1",
        "subgroups": [{
        "__v": 0,
            "_id": "5634fa63f925a0ac02f1b0fc",
            "subgroupname": "subgroup 1",
            "books": [{
            "bookname": {
                "name": "sasasasasasP"
            }
        }]
    }]
}, {
    "__v": 0,
        "_id": "5634fa3df925a0ac02f1b0fd",
        "groupname": "group 2",
        "subgroups": [{
        "__v": 0,
            "_id": "5634fa63f925a0ac02f1befc",
            "subgroupname": "subgroup 2",
            "books": [{
            "bookname": {
                "name": "book 2"
            }
        }]
    }]
}];

除了@Stefan Dochow识别的代码中的其他问题之外，使用变量来识别具有嵌套循环的这种逻辑中的对象总是更好。以下是一个例子：

var apiListData = [];


for (var i = 0, totalGroups = groups.length; i < totalGroups; i++) {
    var group = groups[i];
    var subGroups = group.subgroups;
    for (var j = 0, totalSubGroups = subGroups.length; j < totalSubGroups; j++) {
        var subGroup = subGroups[j];
        var books = subGroup.books;
        for (var k = 0, totalBooks = books.length; k < totalBooks; k++) {
            var book = books[k].bookname;
            apiListData.push({
                groupName: group.groupname,
                subGroupName: subGroup.subgroupname,
                bookName: book.name
            });
        }
    }
}


console.log('apiListData', apiListData);

嵌套循环不形成完整对象 - 问题

2 个答案: