How to sort the select2 (jQuery plugin) options alphabetically?

Question

I want to sort the select2 options in alphabetical order. I have the following code and would like to know, how can this be achieved:

<select name="list" id="mylist" style="width:140px;">
   <option>United States</option>
   <option>Austria</option>
   <option>Alabama</option>    
   <option>Jamaica</option>
   <option>Taiwan</option>
   <option>canada</option>
   <option>palau</option>
   <option>Wyoming</option>
</select>


$('#mylist').select2({
  sortResults: function(results) { return results.sort(); } 
});

I want to sort the data via 'text'.

Answer 1

Select2 API v3.x (sortResults)

You can sort elements using sortResults callback option with String.localeCompare():

$( '#mylist' ).select2({
  /* Sort data using localeCompare */
  sortResults: data => data.sort((a, b) => a.text.localeCompare(b.text)),
});

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/3.5.4/select2.min.css" integrity="sha256-ijlUKKj3hJCiiT2HWo1kqkI79NTEYpzOsw5Rs3k42dI=" crossorigin="anonymous" /><script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/select2/3.5.4/select2.min.js" integrity="sha256-7A2MDY2eGSSUvgfbuH1IdzYk8qkEd3uzwiXADqPDdtY=" crossorigin="anonymous"></script>
<select name="list" id="mylist" style="width:140px;">
   <option>United States</option>
   <option>Austria</option>
   <option>Alabama</option>    
   <option>Jamaica</option>
   <option>Taiwan</option>
   <option>canada</option>
   <option>palau</option>
   <option>Wyoming</option>
</select>

Select2 API v4.0 (sorter)

You can sort elements using sorter callback option:

$('#mylist').select2({
    sorter: data => data.sort((a, b) => a.text.localeCompare(b.text)),
});

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.5/css/select2.css" integrity="sha256-xqxV4FDj5tslOz6MV13pdnXgf63lJwViadn//ciKmIs=" crossorigin="anonymous" /><script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.5/js/select2.min.js" integrity="sha256-FA14tBI8v+/1BtcH9XtJpcNbComBEpdawUZA6BPXRVw=" crossorigin="anonymous"></script>
<select name="list" id="mylist" style="width:140px;">
   <option>United States</option>
   <option>Austria</option>
   <option>Alabama</option>    
   <option>Jamaica</option>
   <option>Taiwan</option>
   <option>canada</option>
   <option>palau</option>
   <option>Wyoming</option>
</select>

---

Without jQuery

I had another general purpose approach (you can use value or an attribute for sorting elements) without using jQuery:

var select = document.getElementById("mylist");
var options = [];
// Get elements to sort
document.querySelectorAll('#mylist > option').forEach(
  option => options.push(option)
);
// Empty select
while (select.firstChild) {
    select.removeChild(select.firstChild);
}
// Sort array using innerText (of each option node)
options.sort(
  (a, b) => a.innerText.localeCompare(b.innerText)
);
// Add the nodes again in order
for (var i in options) {
    select.appendChild(options[i]);
}

<select name="list" id="mylist" style="width:140px;">
   <option>United States</option>
   <option>Austria</option>
   <option>Alabama</option>    
   <option>Jamaica</option>
   <option>Taiwan</option>
   <option>canada</option>
   <option>palau</option>
   <option>Wyoming</option>
</select>

With jQuery

Thanks @Narendra Sisodia for jQuery tip:

/* Get options */
var selectList = $('#mylist > option');
/* Order by innerText (case insensitive) */
selectList.sort(
  (a, b) => a.innerText.localeCompare(b.innerText)
);
/* Re-do select HTML */
$('#mylist').html(selectList);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>
<select name="list" id="mylist" style="width:140px;">
   <option>United States</option>
   <option>Austria</option>
   <option>Alabama</option>    
   <option>Jamaica</option>
   <option>Taiwan</option>
   <option>canada</option>
   <option>palau</option>
   <option>Wyoming</option>
</select>