how to toggle attr() in jquery

Question

I have a simple add attribute function:

$(\".list-toggle\").click(function() {
    $(\".list-sort\").attr(\'colspan\', 6);
});

My question is:

Answer 1

$(".list-toggle").click(function() {
    $(this).hasAttr('colspan') ? 
        $(this).removeAttr('colspan') : $(this).attr('colspan', 6);
});