int ledPin = 7;             // pin for the LED signal

int buttonPin = 2;          // pin for the button signal

int buttonState = 0;        // current state of the button

int lastButtonState = 0;    // previous state of the button

 

void setup() {

  pinMode(ledPin, OUTPUT);

  pinMode(buttonPin, INPUT);

}

void loop() {

  buttonState = digitalRead(buttonPin);

 

  if (buttonState != lastButtonState) { // != is Arduino code for Not Equal to

    if (buttonState == HIGH) {          // == Checks if the value of two operands is equal or  not, if yes then condition becomes true.

      digitalWrite(ledPin, !digitalRead(ledPin)); // toggle the LED

    }

  }

  lastButtonState = buttonState;

}