// Define pin numbers
const int ledPin = 4;   // Pin connected to toggle LED
const int switchPin = 9; // Pin connected to toggle switch

void setup() {
  // Configure the LED pin as an output
  pinMode(ledPin, OUTPUT);
  
  // Configure the switch pin as an input
  pinMode(switchPin, INPUT_PULLUP);  // Use the internal pull-up resistor
}

void loop() {
  // Read the state of the switch
  int switchState = digitalRead(switchPin);
  
  // Check if the switch is pressed (LOW state)
  if (switchState == LOW) {
    // Turn the LED on
    digitalWrite(ledPin, HIGH);
  } else {
    // Turn the LED off
    digitalWrite(ledPin, LOW);
  }
}