Change Icon Open On Button Bootstrap

I am using button with Bootstrap Glyphicon Components and have a lots of buttons on one page, it is using collapse to show hidden section.Here is example codes i have

Working Demo

$(".collapse").collapse()
$("button[data-toggle=collapse]").click(function(){
        $(this).find('span:first').toggleClass('glyphicon-chevron-down glyphicon-chevron-up')
});

<scriptsrc="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><linkhref="https://netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css"rel="stylesheet"/><scriptsrc="https://netdna.bootstrapcdn.com/bootstrap/3.0.0/js/bootstrap.min.js"></script><divclass="container"><divclass="panel-group"id="accordion"><divclass="panel panel-default"><divclass="panel-heading"><h4class="panel-title"><buttontype="button"class="btn btn-primary"data-toggle="collapse"data-target="#demo"><spanclass="glyphicon glyphicon-chevron-down"></span> Open
            </button></h4></div><divid="demo"class="panel-collapse collapse in"><divclass="panel-body">
            Contents:Thank you to help me solve the problem, you're a great guy!
          </div></div></div></div></div>

Solution 2:

$(document).on('click', '[data-toggle="collapse"]', function() {    
    $(this).toggleClass('glyphicon-menu-down glyphicon-menu-up');
});