Get multidimensional array values using string key

This function allows to extract values of multidimensional using string as key chain.

function getSetting($settings, $key, $delimiter = '.')
{
	$keyChain = explode($delimiter, $key);
	$firstKey = array_shift($keyChain);

	if (! array_key_exists($firstKey, $settings)) {
		return null;
	} else if (! $keyChain) {
		return $settings[$firstKey];
	}

	return getSetting($settings[$firstKey], implode($delimiter, $keyChain), $delimiter);
}