//jQuery get class name of element 

var className=$('#myElementID').attr('class');

​

var className = $('#sidebar').attr('class');

​

if ($(".Mandatory").length > 0) {

    // Do stuff with $(".Mandatory")

    $(".Mandatory").each(function() {

        // "this" points to current item in looping through all elements with

        // class="Mandatory"

        $(this).doSomejQueryWithElement();

    }); 

}

​

$("input[type='submit']").click(function() {

    if ($(".Mandatory").length > 0) {

        // Do some code here

    }

});

​

$('.Mandatory').each(function(){

  //do your thing

});

​

if ($('.Mandatory').length > 0) {

  //do your thing

}

​