Answers for "how to get selectpicker value in jquery"

js how to get selectpicker value

$(document).on('change', '#input_id', function() {
    var selected = $('#input_id').val();
});

selectpicker set value jquery

The value is correctly selected, but you didn't see it because the plugin hide the real select and show a button with an unordered list, so, if you want that the user see the selected value on the select you can do something like this:

//Get the text using the value of select
var text = $("select[name=selValue] option[value='1']").text();
//We need to show the text inside the span that the plugin show
$('.bootstrap-select .filter-option').text(text);
//Check the selected attribute for the real select
$('select[name=selValue]').val(1);
Edit:
Like @blushrt points out, a better solution is:

$('select[name=selValue]').val(1);
$('.selectpicker').selectpicker('refresh')
Edit 2:
To select multiple values, pass the values as an array.