const int analogPin = A0;
int ledPins[] = {2, 3, 4, 5, 6};
int num_10bit,num_05;
void setup(){
  // loop over the pin array and set them all to output:
  for (int thisLed = 2; thisLed < ledPins; thisLed++) {
    pinMode(ledPins[thisLed], OUTPUT);
  }
}
void loop(){
  num_10bit=analogRead(analogPin);
  num_05=map(num_10bit,0,1023,0,5);
  led_level();
for (int thisLed = 0; thisLed<5; thisLed++){
  digitalWrite(ledPins[thisLed], LOW);
}
}void led_level(){
  for (int thisLed = 0; thisLed<num_05; thisLed++) {
    digitalWrite(ledPins[thisLed], HIGH);
  }
}