title: xcode: class is not key value coding-compliant
body: <p>I'm currently working myself through this tutorial:
  <a href="https://developer.apple.com/library/content/referencelibrary/GettingStarted/DevelopiOSAppsSwift/ConnectTheUIToCode.html#//apple_ref/doc/uid/TP40015214-CH22-SW1" rel="noreferrer">https://developer.apple.com/library/content/referencelibrary/GettingStarted/DevelopiOSAppsSwift/ConnectTheUIToCode.html#//apple_ref/doc/uid/TP40015214-CH22-SW1</a>
  After creating the function for the button(at ~2/3 on the page) I tried running the code and got the Exception:</p>
  
  <pre><code>2017-12-08 11:24:31.343183+0100 FoodTracker[2159:154603] *** 
  
  Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[&lt;FoodTracker.ViewController 0x7fea6f406820&gt; setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key setDefaultLabelText.'
  *** First throw call stack:
  (
      0   CoreFoundation                      0x0000000109d7512b __exceptionPreprocess + 171
      1   libobjc.A.dylib                     0x00000001060fcf41 objc_exception_throw + 48
      2   CoreFoundation                      0x0000000109d75079 -[NSException raise] + 9
      3   Foundation                          0x0000000105b1ba63 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 292
      4   UIKit                               0x0000000106b39117 -[UIViewController setValue:forKey:] + 87
      5   UIKit                               0x0000000106e2ac2d -[UIRuntimeOutletConnection connect] + 109
      6   CoreFoundation                      0x0000000109d183cd -[NSArray makeObjectsPerformSelector:] + 317
      7   UIKit                               0x0000000106e295e3 -[UINib instantiateWithOwner:options:] + 1856
      8   UIKit                               0x0000000106b403ff -[UIViewController _loadViewFromNibNamed:bundle:] + 383
      9   UIKit                               0x0000000106b40d2b -[UIViewController loadView] + 177
      10  UIKit                               0x0000000106b4105c -[UIViewController loadViewIfRequired] + 195
      11  UIKit                               0x0000000106b418b9 -[UIViewController view] + 27
      12  UIKit                               0x0000000106a0c7cf -[UIWindow addRootViewControllerViewIfPossible] + 122
      13  UIKit                               0x0000000106a0ced7 -[UIWindow _setHidden:forced:] + 294
      14  UIKit                               0x0000000106a1fe54 -[UIWindow makeKeyAndVisible] + 42
      15  UIKit                               0x00000001069928b8 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 4737
      16  UIKit                               0x0000000106997aeb -[UIApplication _runWithMainScene:transitionContext:completion:] + 1720
      17  UIKit                               0x0000000106d616f8 __111-[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:]_block_invoke + 924
      18  UIKit                               0x00000001071374c8 +[_UICanvas _enqueuePostSettingUpdateTransactionBlock:] + 153
      19  UIKit                               0x0000000106d612f1 -[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:] + 249
      20  UIKit                               0x0000000106d61b6b -[__UICanvasLifecycleMonitor_Compatability activateEventsOnly:withContext:completion:] + 696
      21  UIKit                               0x00000001076dfa69 __82-[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:]_block_invoke + 262
      22  UIKit                               0x00000001076df922 -[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:] + 444
      23  UIKit                               0x00000001073bc9c8 __125-[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:]_block_invoke + 221
      24  UIKit                               0x00000001075bbb06 _performActionsWithDelayForTransitionContext + 100
      25  UIKit                               0x00000001073bc88b -[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:] + 231
      26  UIKit                               0x0000000107136b25 -[_UICanvas scene:didUpdateWithDiff:transitionContext:completion:] + 392
      27  UIKit                               0x000000010699636a -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 523
      28  UIKit                               0x0000000106f71605 -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 369
      29  FrontBoardServices                  0x000000010bc38cc0 -[FBSSceneImpl _didCreateWithTransitionContext:completion:] + 338
      30  FrontBoardServices                  0x000000010bc417b5 __56-[FBSWorkspace client:handleCreateScene:withCompletion:]_block_invoke_2 + 235
      31  libdispatch.dylib                   0x000000010ae9733d _dispatch_client_callout + 8
      32  libdispatch.dylib                   0x000000010ae9c9f3 _dispatch_block_invoke_direct + 592
      33  FrontBoardServices                  0x000000010bc6d498 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 24
      34  FrontBoardServices                  0x000000010bc6d14e -[FBSSerialQueue _performNext] + 464
      35  FrontBoardServices                  0x000000010bc6d6bd -[FBSSerialQueue _performNextFromRunLoopSource] + 45
      36  CoreFoundation                      0x0000000109d18101 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
      37  CoreFoundation                      0x0000000109db7f71 __CFRunLoopDoSource0 + 81
      38  CoreFoundation                      0x0000000109cfca19 __CFRunLoopDoSources0 + 185
      39  CoreFoundation                      0x0000000109cfbfff __CFRunLoopRun + 1279
      40  CoreFoundation                      0x0000000109cfb889 CFRunLoopRunSpecific + 409
      41  GraphicsServices                    0x000000010c5019c6 GSEventRunModal + 62
      42  UIKit                               0x00000001069995d6 UIApplicationMain + 159
      43  FoodTracker                         0x00000001057e7b67 main + 55
      44  libdyld.dylib                       0x000000010af13d81 start + 1
  )
  libc++abi.dylib: terminating with uncaught exception of type NSException
  (lldb) 
  </code></pre>
  
  <p>Here is my Code:</p>
  
  <p><img src="https://i.stack.imgur.com/3zDB0.png" alt="Screenshot"></p>
  
  <p>And the connections inspector of the button:</p>
  
  <p><img src="https://i.stack.imgur.com/kJUtM.png" alt="enter image description here"></p>