Undefined array key “HTTP_USER_AGENT”

Since upgrading to PHP8, my logs are full of warnings like:

Undefined array key "HTTP_USER_AGENT" in /wp-content/themes/himalayas/inc/functions.php on line 62

This is because your code doesn’t check for the existence of the key before accessing it:

$himalayas_user_agent = strtolower( $_SERVER['HTTP_USER_AGENT'] );

Please add ‘isset’ check for this key before trying to access it, like so:

$himalayas_user_agent = ( isset($_SERVER['HTTP_USER_AGENT']) ? strtolower( $_SERVER['HTTP_USER_AGENT'] ) : '' );

• This topic was modified 1 year, 2 months ago by mattf10.