<a class="btn btn-lib" role="button" data-toggle="collapse" href="#collapseEX1" aria-expanded="false" aria-controls="collapseEX1">Peeka</a><div class="collapse" id="collapseEX1"> <p>Boo!</p></div>
The button collapse is very similar to the <a> collapse. However, there are a couple differences to make note below.
button
<a>
<button class="btn btn-lib" type="button" data-toggle="collapse" data-target="#collapseEX2" aria-expanded="false" aria-controls="collapseEX2">Peeka</button><div class="collapse" id="collapseEX2"> <p>Boo!</p></div>
<a class="btn btn-lib" role="button" data-toggle="collapse" href="#collapseEX1" aria-expanded="false" aria-controls="collapseEX1">Peeka</a> <div class="collapse" id="collapseEX1"> <p>Boo!</p> </div>
<button class="btn btn-lib" type="button" data-toggle="collapse" data-target="#collapseEX2" aria-expanded="false" aria-controls="collapseEX2">Peeka</button> <div class="collapse" id="collapseEX2"> <p>Boo!</p> </div>
For further information on collapsing elements using buttons and links, see the following sites for further information