$keys = explode('.', $key);
$error = ' is not exists';
$value = false;
foreach ($keys as $val) {
if (! is_array($array)) {
$value = $val . $error;
break;
}
$array = array_key_exists($val, $array) ? $array[$val] : false;
$value = $array;
}
var_dump($value);