title: ios check if nsarray == null
body: <p>I'm receiving some response from <code>JSON</code>, and is working fine, but I need to check for some <code>null</code> values,</p>
  
  <p>I have found different answers but seems is not working still,</p>
  
  <pre><code>NSArray *productIdList = [packItemDictionary objectForKey:@"ProductIdList"];
  </code></pre>
  
  <p>I have tried with</p>
  
  <pre><code>if ( !productIdList.count )  //which breaks the app,
  
  if ( productIdList == [NSNull null] )  // warning: comparison of distinct pointer types (NSArray and NSNull)
  </code></pre>
  
  <p>So what is happening? How to fix this and check for <code>null</code> in my array?</p>
  
  <p>Thanks!</p>