Question

How should I understand

$("select option:selected")

in the following code ?

(taken from here)

$("select").change(function() {
   ...
   $("select option:selected").each(function () {
      ...
   });
   ...
})

Is it all selected options in all selects in the document ?

Is it somehow related to the current select, $(this) ?

Answer 1

Yes, it will refer to all selected options in all selects. If you just want to look at the current select, you can do something like this:

$("select").change(function() {
   ...
   $(this).find("option:selected").each(function () {
      ...
   });
   ...
})