title: ObjC: object returned empty description?
body: <p>My code is reading a list of key/value pairs like follows:</p>
  
  <pre><code>A:nodeAbc
  ...
  Q:node2
  R:
  T:node3
  ...
  </code></pre>
  
  <p>Each pair is split using NSString:componentsSeparatedByString:</p>
  
  <pre><code>NSArray *kv = [@"R:" componentsSeparatedByString:@":"];
  </code></pre>
  
  <p>In the list example above, R has no matching value. As I ask to print it, here is what I get:</p>
  
  <p>(lldb) po [kv objectAtIndex:1]
  (id) $33 = 0x00007fff77a888e0 </p>
  
  <p>How can I identify this?</p>
  
  <pre><code>if ([kv objectAtIndex:1]) // returns YES
  </code></pre>
  
  <p>I'd like it to be treated as a nil, how can it be done?
  Thanks!</p>