JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/sweetalert/1.1.3/sweetalert.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/sweetalert/1.1.3/sweetalert.min.js"></script>
 <select id="dropdownId">
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

JavaScript

var prev_val;
$('#dropdownId').focus(function () {
  prev_val = $(this).val();
}).change(function (e) {
  var select = this;
  $(this).blur();

  var success = confirm('Are you sure you want to change the Dropdown?');
  if (success){
    // Other changed code would be here...
  } else{
    $(this).val(prev_val);
    return false;
  }
});

$('#dropdownId').change(function (e) {
	//Notifies when a value was selected.
  //In case of JS Alert, it emits the right one.
  //In case of SweetAlert, it emits the clicked (but not confirmed) one
  alert($(this).val());
});