int Pin_Nos[6] ={2,5,6,8,11,12};

void setup() {
  Serial.begin(9600);
  Serial.print("First (Index 0)element of array : ");
  Serial.println(Pin_Nos[0]);

  Serial.print("Last (Index 5)element of array : ");
  Serial.println(Pin_Nos[5]);

for(int i =0; i<6; i++)
{
  Serial.print("Element ");
  Serial.print(i);
  Serial.print(" of Array : ");
  Serial.println(Pin_Nos[i]);
  pinMode(Pin_Nos[i], OUTPUT);

}

}

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

}