JQuery :: Get All Attributes Of An Element?

If I have the following hyperlink :

<p><a href='page.htm' id='foo' class='bar' alt='alt text'>click</a></p>

I know that I can get (eg) the href attribute via $('a').attr('href') BUT I would like to do the following :

get *all* the attribute names and values without knowing anything about the attribute names and values in advance (or even how many there are) - something like a loop and $('a').(attribute name, attribute value). I suppose they would best be placed in a JavaScript object as a set of name/value pairs eg { href: 'page.htm', id: 'foo', alt: 'alt text' }