javascript 事先不知道属性名称时如何解析JSON数据？
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How to parse JSON data when the property name is not known in advance?
提问by David Willis
Here is my response code in jQuery:
这是我在 jQuery 中的响应代码：
var response = $.parseJSON(response);
for (var i = 0; i < response.groupIds.length; i++) {
console.log(response.groupIds[i], i);
}
Each response.groupIds[i]is of the form {"unknown name":"unknown value"}.
每个response.groupIds[i]都是形式{"unknown name":"unknown value"}。
I wish to access both of these bits of data in javascript, how do I accomplish this when I don't know in advance what e.g. unknown nameis?
我希望在 javascript 中访问这两个数据位，如果我事先不知道 egunknown name是什么，我该如何实现？
回答by Rob W
Use Object.keysto retrieve a full list (array) of key names. A polyfill is available here.
使用Object.keys检索键名的完整列表（阵列）。一个 polyfill在这里可用。
var group = response.groupIds[i];
var allPropertyNames = Object.keys(group);
for (var j=0; j<allPropertyNames.length; j++) {
var name = allPropertyNames[j];
var value = group[name];
// Do something
}
Your question's response format contains only one key-value pair. The code can then be reduced to:
您问题的响应格式仅包含一个键值对。然后可以将代码简化为：
var group = response.groupIds[i];
var name = Object.keys(group)[0]; // Get the first item of the list; = key name
var value = group[name];
If you're not interested in the list, use a for-i-inloop withhasOwnProperty. The last method has to be used, to exclude properties which are inherit from the prototype.
如果你没有在列表中感兴趣的话，使用for-i-in循环使用hasOwnProperty。必须使用最后一个方法，以排除从原型继承的属性。
for (var name in group) {
if (group.hasOwnProperty(name)) {
var value = group[name];
// Do something
}
}
回答by Niet the Dark Absol
Use a for..inloop:
使用for..in循环：
for( x in response.groupIds[i]) {
// x is now your unknown key
// response.groupIds[i][x] is the unknown value
}
Since there is only one property of the object, that'll work nicely.
由于对象只有一个属性，所以这会很好地工作。
