int switchState = LOW;

const int led = 0;
const int button = 1;

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

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

if (switchState == LOW) {
  digitalWrite(led, LOW);
}

else {
  digitalWrite (led, HIGH);
  }
}