Do browsers parse javascript on every page load?

Do browsers (IE and Firefox) parse linked javascript files every time the page refreshes?

Prevent caching of AJAX call

It looks like that if I load dynamic content using $.get(), the result is cached in browser. Adding some random string in QueryString seem to solve this issue (I use new Date().toString()), but this feels like a hack.

Is there any other way to achieve this? Or, if unique string is the only way to achieve this, any suggestions other than new Date() ?

Source: Tips4all