PHP -Kraft -Array -Schlüssel zu Kleinbuchstaben
$lower_case_keys = array_change_key_case($array, CASE_LOWER);
Matteoweb
$lower_case_keys = array_change_key_case($array, CASE_LOWER);array_walk($yourArray, function(&$value)
{
$value = strtolower($value);
});array_walk($yourArray, function(&$value)
{
$value = strtolower($value);
});