Examples
Toggle contextual overlays for displaying lists of links and more with the Bootstrap dropdown plugin.
Single button dropdowns
                                            Any single .btn can be turned into a
                                            dropdown
                                            toggle with some markup changes. Here’s how you can put them to work
                                            with either <button>
                                            elements:
                                        
Variant
The best part is you can do this with any button variant, too:
Dropend variation
                                            Trigger dropdown menus at the right of the elements by adding
                                            .dropend to the parent element.
                                        
Dropup variation
                                            Trigger dropdown menus above elements
                                            by adding .dropup to the parent
                                            element.
                                        
Active Item
                                            Add .active to item in the dropdown to style them as
                                                active.
                                        
Headers
Add a header to label sections of actions in any dropdown menu.
Forms
Put a form within a dropdown menu, or make it into a dropdown menu, and use margin or padding utilities to give it the negative space you require.
Split button dropdowns
                                            Similarly, create split button dropdowns with virtually the same markup as
                                            single button dropdowns, but with the addition of .dropdown-toggle-split for proper
                                            spacing around the dropdown caret.
                                        
Sizing
Button dropdowns work with buttons of all sizes, including default and split dropdown buttons.
Dropstart variation
                                            Trigger dropdown menus at the right of the elements by adding
                                            .dropstart to the parent element.
                                        
Menu alignment
                                            Add .dropdown-menu-end
                                            to a .dropdown-menu to right
                                            align the dropdown menu.
                                        
Disabled Item
                                            Add .disabled to items in the dropdown to style them as
                                                disabled.
                                        
Text
Place any freeform text within a dropdown menu with text and use spacing utilities. Note that you’ll likely need additional sizing styles to constrain the menu width.