Collapsing content
The visibility of elements can be toggled by applying the collapse
class in conjunction with the data-toggle="collapse"
attribute. Applying the collapse class will simply set the target element's display
property to none
. An element can be animated to become visible again using an anchor
whose data-toggle
attribute is set to collapse
 and whose href
attribute points to the collapsed element using a jQuery selector. Consider this example:
<a href="#my-content" data-toggle="collapse">Toggle my content</a> <div id="my-content" class="collapse bg-secondary text-light"> Lorem ipsum dolor sit amet, consectetur adipiscing elit </div>
Internally, Bootstrap achieves this using the collapseplugin defined in js/src/collapse.js
 (note that you do not need to manually include this file; its contents already come bundled as part of bootstrap.min.js
).
Instead of specifying the target using the href
attribute, one can use the data-target
 attribute along with a jQuery...