const int analogPin = A0;
const int ledCount = 10;

int ledPins[] = {2,3,4,5,6,7,8,9,10,11};

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

void loop(){
  int sensorReading = analogRead(analogPin);
  int ledLevel = map (sensorReading,0, 1023, 0, ledCount);
  for (int i= 0; i < ledCount;i++){
    if (i < ledLevel){
      digitalWrite(ledPins[i], HIGH);
    }
    else{
      digitalWrite(ledPins[i], LOW);
    }
  }
}