set multi select value to select2 code example

Example 1: 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');

Example 2: select2 multiple selected values

in_array($value, $array)