how to change select2 value programmatically - jquery-select2

Question

I have a select2 box in bootstrap modal, I want to change the value of the select2 box but it didn't work.
I tried every single solution in previous posts and results but none of them got it work.
I use select2 4.0.2, I tested:
$('#select_id').val('val').trigger('change.select2');
$('#select_id').val('val').trigger('change');
$('#select_id').val('val').change()
It works one or two times then it stops working (randomly)
It works fine only when I change the select2 back to 3.x.x

Answer 1

$('#select_id').val('val').trigger('change');
is the right way, see here

Answer 2

$('#select_id').select2('val', selectedValue);

Answer 3

For Select2 with Ajax call, I struggled with lot of options, but none worked. Then i came to following solution, which works like charm
$("#select_id").html($("").val('val').text('text')).trigger("change");

Answer 4

To programmatically select an option/item for a Select2 control, use the jQuery
$('#mySelect2').val('1'); // Select the option with a value of '1'
$('#mySelect2').trigger('change'); // Notify any JS components that the value changed
You can also pass an array to val make multiple selections:
$('#mySelect2').val(['1', '2']);
$('#mySelect2').trigger('change'); // Notify any JS components that the value changed

Answer 5

I have used the following code in 4.x.xx version and it is working
$('#select_id').val('val').select2();

Answer 6

If you, like me, have added a custom handler for the select2:selecting event the correct complete answer to changing a value and triggering the custom select2 event would be:
$('#select_id').val('val').trigger('change').trigger({
type: 'select2:event_name', // It worked for me with select2:selecting and select2:select
params: {
args: { // Only use 'args' if using select2:selecting, select2:select does not use it
data: varWithEventData
}
}
});

Answer 7

For those who facing an issue like this:
If you're using multiple select elements and have a common event handler (like $(".mySelect2Inputs").click(...) ) when you do $('#mySelect2').trigger('change') the click event handler is gonna trigger multiple times ($(".mySelect2Inputs").length times).
To prevent this situation, you must use $('#mySelect2').trigger('change.select2') (attention to .select2 namespace!).
From the select2 docs:
https://select2.org/programmatic-control/events#limiting-the-scope-of-the-change-event
It's common for other components to be listening to the change event, or for custom event handlers to be attached that may have side effects. To limit the scope to only notify Select2 of the change, use the .select2 event namespace:
$('#mySelect2').val('US'); // Change the value or make some change to the internal state $('#mySelect2').trigger('change.select2'); // Notify only Select2 of changes