Arduino Reference - BooleanVariables

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## boolean

A boolean holds one of two values, true or false. (Each boolean variable occupies one byte of memory.)

#### Example

    int LEDpin = 5;       // LED on pin 5
    int switchPin = 13;   // momentary switch on 13, other side connected to ground

    boolean running = false;

    void setup()
    {
      pinMode(LEDpin, OUTPUT);
      pinMode(switchPin, INPUT);
      digitalWrite(switchPin, HIGH);      // turn on pullup resistor
    }

    void loop()
    {
      if (digitalRead(switchPin) == LOW)
      {  // switch is pressed - pullup keeps pin high normally
        delay(100);                        // delay to debounce switch
        running = !running;                // toggle running variable
        digitalWrite(LEDpin, running)      // indicate via LED
      }
    }

#### See also

- constants
- boolean operators
- Variable Declaration

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