title: Compare to null in objective c
body: <p>I am beginning to find my code littered with:</p>
  
  <pre><code>if([p objectForKey@"somekey"] != [NSNull null]) {
  
  }
  </code></pre>
  
  <p>Is there shorter (character-wise) comparison for NULL?</p>
  
  <p>Background: I am using the SBJson library to parse a JSON string and there are often null values (by design) for some of the keys.</p>