title: When trying change url on button press I get the error : unexpectedly found nil while unwrapping an Optional value
body: <p>Im using XCODE and Swift 3.</p>
  
  <p>I have an app which allows the user to change what site they are viewing, and which button they press then updates the webview with the new url.</p>
  
  <p>I seem to constantly get this error : "unexpectedly found nil while unwrapping an Optional value"</p>
  
  <p>I am new to Xcode and Swift, this is my first app build. So trying to debug it is proving difficult. I can see that the URL i am using does have a "?" after it. Is there a way I can make the url a non optional value? And when I do, would the webview update accordingly with the new url</p>
  
  <p><a href="https://i.stack.imgur.com/aM39r.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aM39r.png" alt="enter image description here"></a></p>