How to get the language value from $_SERVER['HTTP_ACCEPT_LANGUAGE'] using PHP?

Question

When I use Firefox to test this block of code, I get en-us,en;

Answer 1

As of v5.3 PHP has function for that purpose:

$locale = locale_accept_from_http($_SERVER['HTTP_ACCEPT_LANGUAGE']);

See: http://php.net/manual/en/locale.acceptfromhttp.php