Answers for "select2 select value"

select2 clear options

Remove the selected options : 
-----------------------------
$('#mySelect2').val(null).trigger('change');

============================================

Completly remove the select2 initialization :
--------------------------------------------
$('#payment_method').html('').select2({data: [{id: '', text: ''}]});

how to set value select2

$('#sel_users').select2().trigger('change');

$(document).ready(function(){

  // Initialize Select2
  $('#sel_users').select2();

  // Set option selected onchange
  $('#user_selected').change(function(){
    var value = $(this).val();

    // Set selected 
    $('#sel_users').val(value);
    $('#sel_users').select2().trigger('change');

  });
});

select2 add option

// Set the value, creating a new option if necessary
if ($('#mySelect2').find("option[value='" + data.id + "']").length) {
    $('#mySelect2').val(data.id).trigger('change');
} else { 
    // Create a DOM Option and pre-select by default
    var newOption = new Option(data.text, data.id, true, true);
    // Append it to the select
    $('#mySelect2').append(newOption).trigger('change');
}

select2 multi select

######## In your HTML:
<select class="js-example-basic-multiple" name="states[]" multiple="multiple">
  <option value="AL">Alabama</option>
    ...
  <option value="WY">Wyoming</option>
</select>

####### In your Javascript (external .js resource or <script> tag):
$(document).ready(function() {
    $('.js-example-basic-multiple').select2();
});

######### Get Selected values
$('.js-example-basic-multiple').select2('val')

######## Pre select values on page loads
 $('.js-example-basic-multiple').val(['AL', 'WY']).trigger('change');

select2

<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/select2.min.css" rel="stylesheet" />
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/select2.min.js"></script>

select2 dropdown with option to add new item

$('#select2')
    .select2()
    .on('select2:open', () => {
        $(".select2-results:not(:has(a))").append('<a href="#" style="padding: 6px;height: 20px;display: inline-table;">Create new item</a>');
})