get key name from json object

This is almost exactly the same as this question json get key names as text?, but that response isn't working for me.

I've got a json object

{"userList":[
{"user1":[{"username":"mike","memberSince":"01/03/2011"}]},
{"user2":[{"username":"john","memberSince":"01/05/2011"}]},
]}

The only reason I have a the "user1" and "user2" labels is because I'm storing the userlist by userId in jQuery data, and then stringifying it to put it in a cookie and send it in another page. I know, sounds stupid, but I'm just building some front end stuff to prove a point before doing this properly with a db.

So the

jQuery('div#userList').data('user1',user1JSON);

turns into

{"user1":[{"username":"mike","memberSince":"01/03/2011"}]}

when using

var userlist=JSON.stringify(jQuery('d开发者_如何学编程iv#userList').data());

Because of this, the user info is now a child of the userId, instead of just being a child of userlist.

In order to get the user info, I should be able to say

for(u=0;u<userList.length;u++){
   var userInfo=userList[u][0];
}

but unfortunately this is just giving me an undefined error. If I use

var userInfo = userList[u]['user1'];

I get the user info correctly.

So, can somebody correct me as to why userList[u][0] does not work, OR

explain to me how to use JSON.stringify without adding the userid to the beginning of the string?

That is because the userList[u] returns an object, not an array.

And you cannot access the object properties with an index..

you could try

for(u=0;u<userList.length;u++){
   for (var user in userList[u])
        {
          // user is the key
          // userList[u][user] is the value
          var userInfo=userList[u][user];
        }
}

You can use jQuery each function to iterate.

data=obj.userList
jQuery.each(data, function(key,value){
  var username=value.username;
  var memberSince=value.memberSince;
  ...
}

How about changing your object like this:

{"userList":[
  {"id": "user1", "username": "mike", "memberSince": "01/03/2011"},
  {"id": "user2", "username": "john", "memberSince": "01/05/2011"}
]}

Then, you can index into the userList array more naturally. That's probably more like what your data will eventually look like coming back from a database backend anyway.