Using the id attribute of a select to process JSON data in jQuery

I am dealing with several dynamically updating select boxes, much like a auto website that dynamically updates make, model, etc. Early in my script I identify the changing select, then identify the next select and pull its id from the page like so:

var next_select_id = $(next_select).attr('id');

I call it next_select_id because the HTML ID of any given select corresponds to the parent object type in the JSON response.

In the case of two selects with the ids "A" and开发者_开发问答 "B", upon changing A, next_select_id should be "B". This works later in the page where I generate a URL by concatenating next_select_id with strings (For example, it generates http://testing.com/users/B just fine).

Later on when I attempt to process a JSON file with a parent key based on next_select_id containing names and id values this way:

$.each(data, function(i, j){  
  row = "<option value=\"" + j.next_select_id.id + "\">" + j.next_select_id.name + "</option>";  
  $(row).appendTo(next_select);                     
});

The j.something.id in this case corresponding to the ID of an ActiveRecord object.

It says "Cannot read property 'id' of undefined". Do I need to be converting next_select_id in some way before attempting this? Thanks for your help!

It looks like you already set next_select_id to the ID string. Just remove your extra .id in that $.each and it should work. (If not, please post the code where you set next_select_id for the $.each.)

It seems I was a bit confused about the proper way to use my string assigned to a variable. In the end, the fix was a simple notational change to:

j[next_select_id]["name"]