https://www.amerikanhastanesi.org/App_Themes/AH/assets/js/select.js

1$(document).ready(function () {
2  (function () {
3    var departmanSelectWrapper = $('[data-toggle="departman"]'),
4        doctorSelect = $('[data-toggle="doctors"] select'),
5        selectedDoctor = doctorSelect.val();
6    
7    departmanSelectWrapper.find('select').change(function () {
8      
9      var selectedDepartman = this.value,
10          placeholder = doctorSelect.closest('[data-toggle="doctors"]').attr('data-placeholder');
11      
12      $.get(departmanSelectWrapper.attr('data-ajax-url'), { 'departmentGuidId': selectedDepartman }, function (res) {
13        doctorSelect.children().remove();
14
15       if(res.data.length) {
16        $(res.data).each(function () {
17          doctorSelect.append('<option value="' + this.DoctorName + '">' + this.DoctorName + '</option>');
18        });
19       }  else {
20        doctorSelect.prepend('<option value="' + placeholder + '" selected="selected">' + placeholder + '</option>');
21       }
22        
23        // if (selectedDoctor !== null) {
24        //   doctorSelect.val(selectedDoctor).trigger('change');
25        //   doctorSelect.prepend('<option value="' + placeholder + '">' + placeholder + '</option>');
26        // } else {
27        //   doctorSelect.val(null).trigger('change');
28        //   doctorSelect.prepend('<option value="' + placeholder + '" selected="selected">' + placeholder + '</option>');
29        // }
30        
31      }, 'JSON');
32    });
33    /*	if ($('[data-toggle="departman"] select').val() !== "0") {
34			$('[data-toggle="departman"] select').trigger('change');	
35		}*/
36    // setTimeout(function() {
37    //   if ($('[data-toggle="departman"] select').val() !== "0") {
38    //     console.log("çalıştı");
39    //     $('[data-toggle="departman"] select').trigger('change');	
40    //   }
41    // });
42    
43  })();
44});