Error saying an included library is not

Question

The IDE tells me the included library isn't? I tried restarting the IDE and my computer but it doesn't work. The other libraries work fine it's only with Keyboard that it fails.

My code:

#include <Keyboard.h>

int buttonState = 0;

void setup() {
  pinMode(2, INPUT);
  pinMode(13, OUTPUT);

  Keyboard.begin();
}

void loop() {
  buttonState = digitalRead(2);
  if (buttonState == HIGH) {
    digitalWrite(13, HIGH);
    Keyboard.press('A');
  } else {
    digitalWrite(13, LOW);
    Keyboard.releaseAll();
  }
}

Error log:

Arduino: 1.6.8 (Windows 10), Board: "Arduino/Genuino Uno"

D:\Documents\Test\Test.ino: In function 'void setup()':

Test:9: error: 'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?
   Keyboard.begin();

   ^

D:\Documents\Test\Test.ino: In function 'void loop()':

Test:16: error: 'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?
 Keyboard.press('A');

 ^

Test:19: error: 'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?
     Keyboard.releaseAll();

     ^

exit status 1
'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?

Answer 1

I see you are using an Arduino Uno.

An Arduino Uno cannot act as a USB keyboard - therefore the Keyboard library doesn't exist for it (the file Keyboard.h is seen as being empty).

You can only use Keyboard.h on boards where using Keyboard.h makes any kind of sense, such as the Leonardo.