title: How to detect UIKeyboard "backspace" button touch on UITextField?
body: <p>How can i detect backspace button pressed on <code>UIKeyboard</code>?</p>
  
  <p><img src="https://i.stack.imgur.com/r49uG.png" alt="enter image description here"></p>
  
  <p>thanks</p>
  
  <hr>
  
  <p><strong>EDIT</strong>: Is there any keyboard delegate that returns key pressed value?</p>