How to store the value of a class into a variable?

Question

JavaScript

How can the content of an element's class attribute be stored into a variable if the element has multiple classes?
example
The task before me is this: when hovering over an element, save the value of the attribute into a temporary variable, change the classes, and after removing the hover, return the classes from the variable to their original place. The problem is that I do not know in advance what classes will be there.
I tried this way:
var temp1 = banner.attr('class');
banner.removeClass().addClass("red");
banner.attr(temp1);
but it didn't work (it can be seen in the example)

How would it be done correctly?

Answer 1

var c = $('#item').attr('class');
$('#item').attr('class', c);