title: My array isn't adding objects
body: <p>I'm wondering why <code>myNumber</code> didn't get added to <code>myArray</code>. Sorry, if the answer is really obvious. I'm just stuck in this section in my Objective-C book about arrays.</p>
  
  <pre><code>int main (int argc, char *argv[]) {
      @autoreleasepool {
          NSNumber *myNumber = [NSNumber numberWithInt: 5];
          NSMutableArray *myArray = [NSMutableArray array];
  
          [myArray addObject: myNumber];
  
          NSLog(@"%lu", [myArray count]);
          NSLog(@"%@", [myArray objectAtIndex: 0]);
      }
      return 0;
  }
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>2012-08-02 21:53:30.827 prog[1889:707] 0
  2012-08-02 21:53:30.829 prog[1889:707] (null)
  </code></pre>