Is it possible to use JavaScript to change the meta-tags of the page?

Question

If I put a div in the head and display:none, than use JavaScript to display it, will this work?

Edit:

I have stuff loaded in AJAX. And as my AJAX changes the

Answer 1

Yes, it is.

E.g. to set the meta-description:

document.querySelector('meta[name="description"]').setAttribute("content", _desc);