title: Delete objects (similar objects/duplicates) in coreData
body: <p>I have in my entity an property named cardId.<br>
  Sometimes this cardId is more then once in my entity. I want to delete these duplicates.</p>
  
  <p>How can I find these duplicates and delete them?</p>
  
  <pre><code>allObjects = [__fetchedResultsController fetchedObjects];
  for (Entity *inbox in allObjects) {
  
      [managedObjectContext deleteObject:**objectToDelete**];
  }
  </code></pre>
  
  <p>How can I find these similar objects?  </p>