JAVASCRIPT

select2 get selected value

//get all selected select object
$('#select2Id').find(':selected');

//get all selected value 
$("#select2Id").select2("val");

jquery select2 set value

<select id="lang" >
   <option value="1">php</option>
   <option value="2">asp</option>
   <option value="3">java</option>
</select>

<script>
	$("#lang").select2().select2('val','1');
</script>

Select options of Select2 control based on values using Jquery

$('#mySelect2').val('1'); // Select the option with a value of '1'
$('#mySelect2').trigger('change'); // Notify any JS components that the value changed

get select2 selected value jquery

$('#id :selected').text();

Select options of Select2 control based on values using Jquery

$('#mySelect2').val(['1', '2']);
$('#mySelect2').trigger('change'); // Notify any JS components that the value changed

select2 set value jquery

$('#inputID').select2('data', {id: 100, a_key: 'Lorem Ipsum'});

select2 set value jquery

$('#all_contacts').select2('data', {id: '123', text: 'res_data.primary_email'});