const uint8_t OUTPUT_PINS[] = {6, 7, 8, 9, 10, 11, 12, 13};
const uint8_t LENGTH_OF_OUTPUT_PINS = sizeof(OUTPUT_PINS) / sizeof(OUTPUT_PINS[0]);

void setup() {
  for(uint8_t i = 0; i < LENGTH_OF_OUTPUT_PINS; i++) {
    pinMode(OUTPUT_PINS[i], OUTPUT);
  }

  for(uint8_t i = 0; i < LENGTH_OF_OUTPUT_PINS; i++) {
    digitalWrite(OUTPUT_PINS[i], HIGH);
  }
}

void loop() {}