jQuery 3.2.1, HTML, CSS, JavaScript
No-Library (pure JS), HTML, CSS, JavaScript
This is a simple Twitter Bootstrap 3 template. You can fork it to get a ready to use Bootstrap 3 fiddle.
Example for answer on http://stackoverflow.com/questions/13437446/how-to-display-selected-item-in-bootstrap-button-dropdown-title/22000328?noredirect=1#comment51687750_22000328