title: How to check if value in array is not NULL?
body: <p>So I am parsing a twitter timeline. There is a field called "following" in the JSON response. It should be true or false.</p>
  
  <p>But sometimes the field is missing.</p>
  
  <p>When I do:</p>
  
  <pre><code>NSLog(@"%@", [[[timeline objectAtIndex:i] objectForKey:@"user"] objectForKey:@"following"]);
  </code></pre>
  
  <p>This is the output:</p>
  
  <pre><code>1
  1
  0
  0
  1
  &lt;null&gt;
  1
  1
  </code></pre>
  
  <p>So how to check for those  values?</p>