#define ARRAY_LEN(arr) (sizeof(arr) / sizeof(*arr))
void setup() {
  Serial.begin(115200);
  while(!Serial);

  String items[] = {"A", "BB", "CCC", "DDDD", "EEEEEE"};
  String items2[] = {};
  Serial.println(ARRAY_LEN(items));
  Serial.println(ARRAY_LEN(items2));
  f(items);
  f(items2);
}

void f(String* items) {
  Serial.println(sizeof(items));
}

void loop() {
}