Click triggering anywhere on page

Question

Can anybody see why this triggers when I click anywhere on the page, and not just the specified element?

var ab = function() {
    alert('sup');
}
$(document).on('click', $('.ac'), ab );

Answer 1

Wrong JQuery :Change your code and try

 $(document).on('click',  '.ac', ab ){

 // do some thing 
};

As @Adeno mentioned in existing comment on() does not accept a jQuery object as it's second argument, only strings should be used for the selector.