如何在.data（）中添加文本？

I have this ajax:

$.ajax({
    method: "GET",
    url: $('.item').data('query_selector'),
    dataType: "html"

(It works fine, and it calls back something like "item=Mann+Co.+Supply+Crate&quality=6&tradable=1&craftable=1&numeric=crate&comparison=eq&value=47&australium=-1")

Now, in order to be valid, it needs to be "/classifieds?(query_selector)"(So in the case above, "/classidieds?item=Mann+Co.+Supply+Crate&quality=6&tradable=1&craftable=1&numeric=crate&comparison=eq&value=47&australium=-1") How would I do this?

put the url string out of ajax

var requestString = '/classifieds?' + $('.item').data('query_selector');

$.ajax({
  method: "GET",
  url: requestString,
  dataType: "html"
});