Auto highlight selected value for bootstrap-select.

demo.js

(function() {
  $(".selectpicker").on("loaded.bs.select", function(e) {
      if ($(this).val() > 0) {
          $(this).selectpicker('setStyle', 'btn-warning', 'add');
      }
  }).on("changed.bs.select", function(e) {
      if ($(this).val() > 0) {
          $(this).selectpicker('setStyle', 'btn-warning', 'add');
      } else {
          $(this).selectpicker('setStyle', 'btn-warning', 'remove');
          $(this).selectpicker('setStyle', 'btn-default', 'add');
      }
  });
}());