const int numLED = 4; 
const int pinLED[numLED] = {8,9,10,11};
void setup() { 
  for(int i=0; i<4; i++){ 
    pinMode(pinLED[i], OUTPUT); 
  } 
} 
void loop() { 
  led_mati();
  led_nyala();
} 
void led_mati(){
  for(int i=0; i<4; i++){ 
    digitalWrite(pinLED[i], LOW); 
  } 
  delay(300); 
}
void led_nyala(){
  for(int i=0; i<4; i++){ 
    digitalWrite(pinLED[i], HIGH); 
    delay(100); 
  } 
}