How to set selected value of jquery select2?

Question

This belong to codes prior to select2 version 4

I have a simple code of select2 that get data from ajax

Answer 1

I did something like this to preset elements in select2 ajax dropdown

      //preset element values
        $(id).val(topics);
       //topics is an array of format [{"id":"","text":""}, .....]
          setTimeout(function(){
           ajaxTopicDropdown(id,
                2,location.origin+"/api for gettings topics/",
                "Pick a topic", true, 5);                      
            },1);
        // ajaxtopicDropdown is dry fucntion to get topics for diffrent element and url