Select2 demo
by Lardpower
HTML
<script src="https://rawgit.com/select2/select2/master/dist/js/select2.js"></script>
<link rel="stylesheet" href="https://rawgit.com/select2/select2/master/dist/css/select2.min.css">
<select id="example" multiple="multiple" style="width: 300px">
<option value="JAN">January</option>
<option value="FEB">February</option>
<option value="MAR">March</option>
<option value="APR">April</option>
<option value="MAY">May</option>
<option value="JUN">June</option>
<option value="JUL">July</option>
<option value="AUG">August</option>
<option value="SEP">September</option>
<option value="OCT">October</option>
<option value="NOV">November</option>
<option value="DEC">December</option>
</select>
<div id="some-other-element">
</div>
JavaScript
$('#example').select2({
placeholder: 'Select a month'
});
const values = ['JUN', 'JUL', 'AUG'];
$('div#some-other-element').attr('values', JSON.stringify(values));
// через 3 секунды после открытия страницы будут установлены летние месяцы
setTimeout(() => {
const currentValues = JSON.parse($('div#some-other-element').attr('values'));
$('#example').val(currentValues);
$('#example').trigger('change');
}, 3000)