title: Obj-C determing integer values with isKindOfClass
body: <p>I need to check the type of each element in an array...</p>
  
  <pre><code>for(id obj in items) {
      if([obj isKindOfClass:[NSString class]]) {
         //handle string case
      } else if([obj isKindOfClass:[NSInteger class]]) {  //THIS LINE GIVES ERROR
         //handle int case
      }
  }
  </code></pre>
  
  <p>Of course <code>NSInteger</code> is just an alias for <code>int</code>, so how can I check for this at runtime?</p>