how to get class name in jquery

1//jQuery get class name of element 
2var className=$('#myElementID').attr('class');
3

1var className = $('#sidebar').attr('class');
2

1if ($(".Mandatory").length > 0) {
2    // Do stuff with $(".Mandatory")
3    $(".Mandatory").each(function() {
4        // "this" points to current item in looping through all elements with
5        // class="Mandatory"
6        $(this).doSomejQueryWithElement();
7    }); 
8}
9

1$("input[type='submit']").click(function() {
2    if ($(".Mandatory").length > 0) {
3        // Do some code here
4    }
5});
6

1if ($('.Mandatory').length > 0) {
2  //do your thing
3}
4

1$('.Mandatory').each(function(){
2  //do your thing
3});
4