Accordions

Bootstrap 4
Bootstrap 3

Standard Accordions with Bootstrap 4

You can create accordions with very reduced code:

Markup

<div class="accordion" id="accordion">
 <accordion parent="accordion" heading="SECTION1" class="show">
   Lorem ipsum...
 </accordion>
 <accordion parent="accordion" heading="SECTION2">
   Lorem ipsum...
 </accordion>
</div>

Result

Lorem ipsum...

HTML

<div class="accordion mb-4" id="accordion"> 
        <div class="card"> 
                <div class="card-header" id="accordion1Heading"> 
                        <h2 class="mb-0"> 
                                <button class="btn btn-link" type="button" data-toggle="collapse" data-parent="#accordion" data-target="#accordion1" aria-expanded="true" aria-controls="accordion1"> 
                                        SECTION1 
                                </button> 
                        </h2> 
                </div> 
                <div id="accordion1" class="collapse show" aria-labelledby="accordion1Heading" data-parent="#accordion" style=""> 
                        <div class="card-body">Lorem ipsum...</div> 
                </div> 
        </div> 
        <div class="card"> 
                <div class="card-header" id="accordion2Heading"> 
                        <h2 class="mb-0">       
                                <button class="btn btn-link collapsed" type="button" data-toggle="collapse" data-parent="#accordion" data-target="#accordion2" aria-expanded="false" aria-controls="accordion2"> 
                                        SECTION2 
                                </button> 
                        </h2> 
                </div>                  
                <div id="accordion2" class="collapse" aria-labelledby="accordion2Heading" data-parent="#accordion" style=""> 
                        <div class="card-body">Lorem ipsum...</div> 
                </div> 
        </div>                  
</div>

Standard Accordions with Bootstrap 3

You can create accordions with very reduced code:

Markup

<div class="panel-group" id="accordion">
 <accordion parent="accordion" heading="SECTION1" class="in">
   Lorem ipsum...
 </accordion>
 <accordion parent="accordion" heading="SECTION2">
   Lorem ipsum...
 </accordion>
</div>

Result

Lorem ipsum...

HTML

 <div id="accordion" class="panel-group">
   <div class="panel panel-default">
     <div class="panel-heading">
       <h4 class="panel-title">
         <a href="#accordion1" data-parent="#accordion" data-toggle="collapse">
           SECTION1
         </a>
       </h4>
     </div>
     <div class="panel-collapse collapse in" id="accordion1">
       <div class="panel-body">
         Lorem ipsum...
       </div>
     </div>
   </div>
   <div class="panel panel-default">
    <div class="panel-heading">
       <h4 class="panel-title">
         <a href="#accordion2" data-parent="#accordion" data-toggle="collapse">
           SECTION2
         </a>
       </h4>
     </div>
     <div class="panel-collapse collapse" id="accordion2">
       <div class="panel-body">
         Lorem ipsum...
       </div>
     </div>
   </div>
 </div>