Javascript 列为未定义的JSON对象元素（在使用`jQuery.parseJSON（）`之前和之后都进行了测试）
我试图通过迭代一个JSON对象来填充一个下拉列表，并用Javascript 列为未定义的JSON对象元素（在使用`jQuery.parseJSON（）`之前和之后都进行了测试）,javascript,ajax,json,Javascript,Ajax,Json,我试图通过迭代一个JSON对象来填充一个下拉列表，并用row.id附加每个的值=，以及标记与row.name之间的实际值 编辑 我忘了提到所传递的数据已经过Ajax处理，是PHP调用数据库的结果 问题是，在填充列表时，每个条目都列为未定义的。id也一样。我一定是做错了，我只是不知道是什么。这是我拥有的阵列： [{ "id": "1", "0": "1", "parent": "0", "1": "0", "name": "Automotive",
row.id值=row.name未定义的id [{
"id": "1",
"0": "1",
"parent": "0",
"1": "0",
"name": "Automotive",
"2": "Automotive",
"description": null,
"3": null,
"ordering": "0",
"4": "0",
"pub
lished": "1",
"5": "1"
}, {
"id": "2",
"0": "2",
"parent": "0",
"1": "0",
"name": "Aerospace",
"2": "Aerospace",
"description": null,
"3": null,
"ordering
": "1",
"4": "1",
"published": "1",
"5": "1"
}, {
"id": "3",
"0": "3",
"parent": "0",
"1": "0",
"name": "Agricultural",
"2": "Agricultural",
"description": null,
"3": null,
"ordering": "2",
"4": "2",
"published": "1",
"5": "1"
}, {
"id": "4",
"0": "4",
"parent": "0",
"1": "0",
"name": "Audiovisual",
"2": "Audiovisual",
"description": null,
"3": null,
"ordering": "3",
"4": "3",
"published": "1",
"5": "1"
}, {
"id": "5",
"0": "5",
"parent": "0",
"1": "0",
"name": "
Construction",
"2": "Construction",
"description": null,
"3": null,
"ordering": "4",
"4": "4",
"published": "1",
"5": "1"
}, {
"id": "6",
"0": "6",
"parent": "0",
"1": "0",
"name": "Energy",
"2": "Energy",
"description": null,
"3": null,
"ordering": "6",
"4": "6",
"published": "1",
"5": "1"
}, {
"id": "7",
"
0": "7",
"parent": "0",
"1": "0",
"name": "Electronics",
"2": "Electronics",
"description": null,
"3": null,
"ordering": "7",
"4": "7",
"published": "1
",
"5": "1"
}, {
"id": "8",
"0": "8",
"parent": "0",
"1": "0",
"name": "Electrical",
"2": "Electrical",
"description": null,
"3": null,
"ordering": "8",
"4
": "8",
"published": "1",
"5": "1"
}, {
"id": "9",
"0": "9",
"parent": "0",
"1": "0",
"name": "Entertainment",
"2": "Entertainment",
"description": null,
"3": null,
"ordering": "9",
"4": "9",
"published": "1",
"5": "1"
}, {
"id": "10",
"0": "10",
"parent": "0",
"1": "0",
"name": "Manufacturing",
"2": "Manufa
cturing",
"description": null,
"3": null,
"ordering": "9",
"4": "9",
"published": "1",
"5": "1"
}, {
"id": "11",
"0": "11",
"parent": "0",
"1": "0",
"name": "Medical",
"2": "Medical",
"description": null,
"3": null,
"ordering": "11",
"4": "11",
"published": "1",
"5": "1"
}, {
"id": "12",
"0": "12",
"parent": "0",
"1": "0",
"name": "Marine",
"2": "Marine",
"description": null,
"3": null,
"ordering": "12",
"4": "12",
"published": "1",
"5": "1"
}, {
"id": "13",
"0": "13",
"parent": "0",
"1": "0",
"name": "Home Applicances",
"2": "Home Applicances",
"description": null,
"3": null,
"ordering": "13",
"4": "13",
"published": "1",
"5": "1"
}, {
"id": "14",
"0": "14",
"parent": "0",
"1": "0",
"name": "Software",
"2": "Software",
"description": null,
"3": null,
"ordering": "14",
"4": "14",
"published": "1",
"5": "1"
}, {
"id": "15",
"0": "15",
"parent": "0",
"1": "0",
"name": "Theoretical work",
"2": "Theoretical work",
"description": null,
"3": null,
"ordering": "15",
"4": "15",
"published": "1",
"5": "1"
}, {
"id": "16",
"0": "16",
"parent": "0",
"1": "0",
"name": "Railroad",
"2": "Railroad",
"description": null,
"3": null,
"ordering": "16",
"4": "16",
"published": "1",
"5": "1"
}, {
"id": "77",
"0": "77",
"parent": "0",
"1": "0",
"name": "Chemistry",
"2": "Chemistry",
"description": null,
"3": null,
"ordering": "5",
"4": "5",
"published": "1",
"5": "1"
}, {
"id": "158",
"0": "158",
"parent": "0",
"1": "0",
"name": "Empty Category",
"2": "Empty Category",
"description": null,
"3": null,
"ordering": "17",
"4": "17",
"published": "1",
"5": "1"
}]
function printSubCategories(categories) {
for (var row in categories) {
rowParsed = jQuery.parseJSON(row);
var opt = document.createElement('option');
if (categories.hasOwnProperty(row)) {
opt.text = rowParsed.name;
opt.value = rowParsed.id;
}
jQuery('#subcategories').append(opt);
}
}
if (categories.hasOwnProperty(row)) {
idParsed = jQuery.parseJSON(row.id);
nameParsed = jQuery.parseJSON(row.name)
opt.text = idParsed;
opt.value = nameParsed;
}
仍然不工作…我认为问题在于你做了太多的解析和检查。如果上面描述的对象是用Javascript正确创建的，则不需要使用解析函数。只有当通过PHP或从DOM中以字符串形式检索对象时，才真正需要这些 您没有指定
类别是什么。我不知道是对象数组还是对象数组的每次迭代，但不管怎样，我认为你的步骤太多了。要做到这一点，你应该只需要这个
…假设categories
是整个对象数组
for(var obj in arr){
var opt = document.createElement('option');
if(obj['id'] && obj['name']){
opt.text = obj['id'];
opt.value = obj['name'];
}
$('#subcategories').append(opt);
}
for（变量i=0；i
或者您可以使用$。每个，都会更好。在数据的意外区域中有一些换行符。比如说，在
[{
"id": "1",
"0": "1",
"parent": "0",
"1": "0",
"name": "Automotive",
"2": "Automotive",
"description": null,
"3": null,
"ordering": "0",
"4": "0",
"pub
lished": "1",
"5": "1"
}
在发布的
中有一个换行符，它使JSON无效。删除所有这些换行符将使JSON有效，并且可以再次解析
在这里测试json，看看它是否是有效的json
编辑：
好的，我在JSFIDLE上尝试了代码，这让我意识到json实际上是如何格式化的。数组中有一些对象，这意味着您只需循环数组，然后像平常一样访问对象
看到这个了吗
我试过这个，它对我有效
var myObj = [
{
"0": "1",
"1": "0",
"2": "Automotive",
"3": null,
"4": "0",
"5": "1",
"id": "1",
"parent": "0",
"name": "Automotive",
"description": null,
"ordering": "0",
"published": "1"
},
{
"0": "2",
"1": "0",
"2": "Aerospace",
"3": null,
"4": "1",
"5": "1",
"id": "2",
"parent": "0",
"name": "Aerospace",
"description": null,
"ordering": "1",
"published": "1"
},
{
"0": "3",
"1": "0",
"2": "Agricultural",
"3": null,
"4": "2",
"5": "1",
"id": "3",
"parent": "0",
"name": "Agricultural",
"description": null,
"ordering": "2",
"published": "1"
},
{
"0": "4",
"1": "0",
"2": "Audiovisual",
"3": null,
"4": "3",
"5": "1",
"id": "4",
"parent": "0",
"name": "Audiovisual",
"description": null,
"ordering": "3",
"published": "1"
},
{
"0": "5",
"1": "0",
"2": "Construction",
"3": null,
"4": "4",
"5": "1",
"id": "5",
"parent": "0",
"name": "Construction",
"description": null,
"ordering": "4",
"published": "1"
},
{
"0": "6",
"1": "0",
"2": "Energy",
"3": null,
"4": "6",
"5": "1",
"id": "6",
"parent": "0",
"name": "Energy",
"description": null,
"ordering": "6",
"published": "1"
},
{
"0": "7",
"1": "0",
"2": "Electronics",
"3": null,
"4": "7",
"5": "1",
"id": "7",
"parent": "0",
"name": "Electronics",
"description": null,
"ordering": "7",
"published": "1"
},
{
"0": "8",
"1": "0",
"2": "Electrical",
"3": null,
"4": "8",
"5": "1",
"id": "8",
"parent": "0",
"name": "Electrical",
"description": null,
"ordering": "8",
"published": "1"
},
{
"0": "9",
"1": "0",
"2": "Entertainment",
"3": null,
"4": "9",
"5": "1",
"id": "9",
"parent": "0",
"name": "Entertainment",
"description": null,
"ordering": "9",
"published": "1"
},
{
"0": "10",
"1": "0",
"2": "Manufacturing",
"3": null,
"4": "9",
"5": "1",
"id": "10",
"parent": "0",
"name": "Manufacturing",
"description": null,
"ordering": "9",
"published": "1"
},
{
"0": "11",
"1": "0",
"2": "Medical",
"3": null,
"4": "11",
"5": "1",
"id": "11",
"parent": "0",
"name": "Medical",
"description": null,
"ordering": "11",
"published": "1"
},
{
"0": "12",
"1": "0",
"2": "Marine",
"3": null,
"4": "12",
"5": "1",
"id": "12",
"parent": "0",
"name": "Marine",
"description": null,
"ordering": "12",
"published": "1"
},
{
"0": "13",
"1": "0",
"2": "Home Applicances",
"3": null,
"4": "13",
"5": "1",
"id": "13",
"parent": "0",
"name": "Home Applicances",
"description": null,
"ordering": "13",
"published": "1"
},
{
"0": "14",
"1": "0",
"2": "Software",
"3": null,
"4": "14",
"5": "1",
"id": "14",
"parent": "0",
"name": "Software",
"description": null,
"ordering": "14",
"published": "1"
},
{
"0": "15",
"1": "0",
"2": "Theoretical work",
"3": null,
"4": "15",
"5": "1",
"id": "15",
"parent": "0",
"name": "Theoretical work",
"description": null,
"ordering": "15",
"published": "1"
},
{
"0": "16",
"1": "0",
"2": "Railroad",
"3": null,
"4": "16",
"5": "1",
"id": "16",
"parent": "0",
"name": "Railroad",
"description": null,
"ordering": "16",
"published": "1"
},
{
"0": "77",
"1": "0",
"2": "Chemistry",
"3": null,
"4": "5",
"5": "1",
"id": "77",
"parent": "0",
"name": "Chemistry",
"description": null,
"ordering": "5",
"published": "1"
},
{
"0": "158",
"1": "0",
"2": "Empty Category",
"3": null,
"4": "17",
"5": "1",
"id": "158",
"parent": "0",
"name": "Empty Category",
"description": null,
"ordering": "17",
"published": "1"
}];
$.each(myObj, function(k, v) {
var opt = document.createElement('option');
$(opt).attr('value', v.id).html(v.name).appendTo($('#mySelect'));
});
我应该指定数组来自php数据库调用。好的，在这种情况下，首先尝试只调用JSON.parse（），一旦在初始对象数组上调用，就不需要在每次迭代中调用它。一旦你这样做了，console.log（）就会分析结果，看看会发生什么，这可能有助于判断出哪里出了问题。我已经尝试过这个方法，但不幸的是，它不起作用。我忘了提到收到的数据来自一个PHP数据库调用。如何准确地$。每个都会更好？你能告诉我为什么在属性名称的某个部分有很多换行符吗？为什么要复制所有的数据？好眼力，但这不是问题：格式化我帖子的人是偶然做的。我刚刚验证过，它是有效的。请看一下JSFIDLE。我相信我已经找到了解决办法
var myObj = [
{
"0": "1",
"1": "0",
"2": "Automotive",
"3": null,
"4": "0",
"5": "1",
"id": "1",
"parent": "0",
"name": "Automotive",
"description": null,
"ordering": "0",
"published": "1"
},
{
"0": "2",
"1": "0",
"2": "Aerospace",
"3": null,
"4": "1",
"5": "1",
"id": "2",
"parent": "0",
"name": "Aerospace",
"description": null,
"ordering": "1",
"published": "1"
},
{
"0": "3",
"1": "0",
"2": "Agricultural",
"3": null,
"4": "2",
"5": "1",
"id": "3",
"parent": "0",
"name": "Agricultural",
"description": null,
"ordering": "2",
"published": "1"
},
{
"0": "4",
"1": "0",
"2": "Audiovisual",
"3": null,
"4": "3",
"5": "1",
"id": "4",
"parent": "0",
"name": "Audiovisual",
"description": null,
"ordering": "3",
"published": "1"
},
{
"0": "5",
"1": "0",
"2": "Construction",
"3": null,
"4": "4",
"5": "1",
"id": "5",
"parent": "0",
"name": "Construction",
"description": null,
"ordering": "4",
"published": "1"
},
{
"0": "6",
"1": "0",
"2": "Energy",
"3": null,
"4": "6",
"5": "1",
"id": "6",
"parent": "0",
"name": "Energy",
"description": null,
"ordering": "6",
"published": "1"
},
{
"0": "7",
"1": "0",
"2": "Electronics",
"3": null,
"4": "7",
"5": "1",
"id": "7",
"parent": "0",
"name": "Electronics",
"description": null,
"ordering": "7",
"published": "1"
},
{
"0": "8",
"1": "0",
"2": "Electrical",
"3": null,
"4": "8",
"5": "1",
"id": "8",
"parent": "0",
"name": "Electrical",
"description": null,
"ordering": "8",
"published": "1"
},
{
"0": "9",
"1": "0",
"2": "Entertainment",
"3": null,
"4": "9",
"5": "1",
"id": "9",
"parent": "0",
"name": "Entertainment",
"description": null,
"ordering": "9",
"published": "1"
},
{
"0": "10",
"1": "0",
"2": "Manufacturing",
"3": null,
"4": "9",
"5": "1",
"id": "10",
"parent": "0",
"name": "Manufacturing",
"description": null,
"ordering": "9",
"published": "1"
},
{
"0": "11",
"1": "0",
"2": "Medical",
"3": null,
"4": "11",
"5": "1",
"id": "11",
"parent": "0",
"name": "Medical",
"description": null,
"ordering": "11",
"published": "1"
},
{
"0": "12",
"1": "0",
"2": "Marine",
"3": null,
"4": "12",
"5": "1",
"id": "12",
"parent": "0",
"name": "Marine",
"description": null,
"ordering": "12",
"published": "1"
},
{
"0": "13",
"1": "0",
"2": "Home Applicances",
"3": null,
"4": "13",
"5": "1",
"id": "13",
"parent": "0",
"name": "Home Applicances",
"description": null,
"ordering": "13",
"published": "1"
},
{
"0": "14",
"1": "0",
"2": "Software",
"3": null,
"4": "14",
"5": "1",
"id": "14",
"parent": "0",
"name": "Software",
"description": null,
"ordering": "14",
"published": "1"
},
{
"0": "15",
"1": "0",
"2": "Theoretical work",
"3": null,
"4": "15",
"5": "1",
"id": "15",
"parent": "0",
"name": "Theoretical work",
"description": null,
"ordering": "15",
"published": "1"
},
{
"0": "16",
"1": "0",
"2": "Railroad",
"3": null,
"4": "16",
"5": "1",
"id": "16",
"parent": "0",
"name": "Railroad",
"description": null,
"ordering": "16",
"published": "1"
},
{
"0": "77",
"1": "0",
"2": "Chemistry",
"3": null,
"4": "5",
"5": "1",
"id": "77",
"parent": "0",
"name": "Chemistry",
"description": null,
"ordering": "5",
"published": "1"
},
{
"0": "158",
"1": "0",
"2": "Empty Category",
"3": null,
"4": "17",
"5": "1",
"id": "158",
"parent": "0",
"name": "Empty Category",
"description": null,
"ordering": "17",
"published": "1"
}];
$.each(myObj, function(k, v) {
var opt = document.createElement('option');
$(opt).attr('value', v.id).html(v.name).appendTo($('#mySelect'));
});