const int analogPin = 0;
const int ledCount = 10;
int ledPins[]={
  2,3,4,5,6,7,8,9,10,11
};
void setup(){
  for(int thisLed= 0;thisLed<ledCount;thisLed++){
    pinMode(ledPins[thisLed],OUTPUT);
  }
}
void loop(){
  int sensorReading = analogRead(analogPin);
  int ledLevel = map(sensorReading,0,1023,0,ledCount);

  for(int thisLed=0;thisLed<ledCount;thisLed++){
    if(thisLed<ledLevel){
      digitalWrite(ledPins[thisLed],HIGH);
    }
    else{
      digitalWrite(ledPins[thisLed],LOW);
    }
  }
}