int arrayled[8]={2,3,4,5,6,7,8,9};

void setup() {
  for(int i=0; i<=7; i++){
    pinMode(arrayled[i],OUTPUT);
  }
}

void loop() {
for(int i=0; i<=7; i++){
  digitalWrite(arrayled[i], HIGH);
  delay(200);
  digitalWrite(arrayled[i], LOW);
  delay(200);
}
}