int ledPins[] = {10, 11, 12, 13}; // deklarasikan pin kedalam array

void setup() {
  //setting smua pin untuk perintahkan output
  for (int i = 0; i < 4; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

void loop() {
  // Iterate through each LED pin
  for (int i = 0; i < 4; i++) {
    digitalWrite(ledPins[i], HIGH); // Turn the LED on
    delay(1000);                    // Wait for 1 second
    digitalWrite(ledPins[i], LOW);  // Turn the LED off
  }
}