#define LEDpin 2
#define button 3

int buttonState = 0;

void setup() {
  pinMode(LEDpin, OUTPUT);
  pinMode(button, INPUT_PULLUP);
}

void loop() {
  buttonState =  digitalRead(button);

  if(buttonState == LOW){
    digitalWrite(LEDpin, HIGH);
  }
  else {
    digitalWrite(LEDpin, LOW);
  }
}