Changing selection in a select with the Chosen plugin

From the "Updating Chosen Dynamically" section in the docs: You need to trigger the 'chosen:updated' event on the field

$(document).ready(function() {    $('select').chosen();    $('button').click(function() {        $('select').val(2);        $('select').trigger("chosen:updated");    });});

NOTE: versions prior to 1.0 used the following:

$('select').trigger("liszt:updated");

My answer is late, but i want to add some information that is missed in all above answers.

1) If you want to select single value in chosen select.

$('#select-id').val("22").trigger('chosen:updated');

2) If you are using multiple chosen select, then may you need to set multiple values at single time.

$('#documents').val(["22", "25", "27"]).trigger('chosen:updated');

Information gathered from following links:
1) Chosen Docs
2) Chosen Github Discussion

Sometimes you have to remove the current options in order to manipulate the selected options.

Here is an example how to set options:

<select id="mySelectId" class="chosen-select" multiple="multiple">  <option value=""></option>  <option value="Argentina">Argentina</option>  <option value="Germany">Germany</option>  <option value="Greece">Greece</option>  <option value="Japan">Japan</option>  <option value="Thailand">Thailand</option></select><script>activateChosen($('body'));selectChosenOptions($('#mySelectId'), ['Argentina', 'Germany']);function activateChosen($container, param) {    param = param || {};    $container.find('.chosen-select:visible').chosen(param);    $container.find('.chosen-select').trigger("chosen:updated");}function selectChosenOptions($select, values) {    $select.val(null);                                  //delete current options    $select.val(values);                                //add new options    $select.trigger('chosen:updated');}</script>

JSFiddle (including howto append options):https://jsfiddle.net/59x3m6op/1/