Twitter bootstrap 3.0 icon change on collapse

Question

This is about Bootstrap 3.0. I would like the icon/glyphicon to change on collapse. I.e, from a closed folder to an open one.

I have searched far and wide, and have

Answer 1

For bootstrap collapse plus and minus sign button.

HTML

  
    
Others
  
  

    
Others are
  

Javascript

$(document).ready(function () {
     $('.collapse')
         .on('shown.bs.collapse', function() {
             $(this)
                 .parent()
                 .find(".glyphicon-plus")
                 .removeClass("glyphicon-plus")
                 .addClass("glyphicon-minus");
             })
         .on('hidden.bs.collapse', function() {
             $(this)
                 .parent()
                 .find(".glyphicon-minus")
                 .removeClass("glyphicon-minus")
                 .addClass("glyphicon-plus");
             });
         });