int pinLed [9] = {12,11,10,9,8,7,6,5,4}; // VARIAVEL ESPECIAL
int numeroLed; // QUAL LED ESTARA ACESSO


void setup() {
  // put your setup code here, to run once:
int x;

 for (x = 0; x <= 8; x = x + 1) { // o comando FOR vai repetir o pinMode seguindo a igualdade de x
  pinMode (pinLed[x], OUTPUT); // vamos colocar a variavel pinLed pegando a variavel x
  }

}

void loop() {
    // put your main code here, to run repeatedly:


for (numeroLed = 0; numeroLed <= 8; numeroLed = numeroLed + 1) {
    digitalWrite (pinLed[numeroLed], HIGH);
    delay (100);
   }

for (numeroLed = 8; numeroLed >= 0; numeroLed = numeroLed - 1) {
    digitalWrite (pinLed[numeroLed], LOW);
    delay (50);
    }
  
}