// https://arduinogetstarted.com/faq/how-to-pass-array-to-function-in-arduino
// https://academy.programmingelectronics.com/pass-array-to-function-in-arduino/
// https://www.geeksforgeeks.org/cpp/cpp-arrays/
// https://publications.gbdirect.co.uk/c_book/chapter5/pointers.html

int array_1[] = { 1, 2 };
int length_1 = sizeof(array_1) / sizeof(array_1[0]);
int array_2[] = { 3, 4, 5, 6 };
int length_2 = sizeof(array_2) / sizeof(array_2[0]);

byte thisOne = 1; // 0 array type, 1 pointer type

void setup() {
  Serial.begin(115200);

  if (thisOne == 0) {
    // pass an array by ARRAY type
    passByArrayType(array_1, length_1);
    passByArrayType(array_2, length_2);
  } else {
    // pass an array by POINTER type
    int *pointer_1 = array_1;
    int *pointer_2 = array_2;
    passByPointerType(pointer_1, length_1);
    passByPointerType(pointer_2, length_2);
  }
}

void loop() {
}

void passByArrayType(int myArray[], int length) {
  Serial.print("BY ARRAY TYPE ");
  for (byte i = 0; i < length; i++) {
    Serial.print(myArray[i]);
  }
  Serial.println();
}

void passByPointerType(int* myPointer, int length) {  // note: initializing argument 1 of 'void passByPointerType(int*, int)'
  Serial.print("BY POINTER TYPE ");
  for (byte i = 0; i < length; i++) {
    Serial.print(*(myPointer + i));
  }
  Serial.println();
}