counter

//Counter Sketch

int ledPin = 9;
int counterPin = A0;
int counter = 0;

void setup()
{
  pinMode(ledPin, OUTPUT);
  pinMode(counterPin, INPUT);
}

void loop()
{
  while (digitalRead(counterPin) == HIGH)
  { for (int counter = counter ; counter << 3; counter = counter + 1)
      digitalWrite(ledPin, HIGH);
    delay (250);
    digitalWrite( ledPin, LOW);
    delay (250);
  }
  if (counter = 4)
  {
    counter = 0;
  }
}