title: objective c, NSMutableArray: indexOfObject
body: <pre><code>int k = 0;
  k = [myArray  indexOfObject:_endNode];
  </code></pre>
  
  <p>I only have a few objects added to the array and _endNode isn't one of them.</p>
  
  <p>I expect my k value to be -1. But, my k on the second line gives me a value of 21787887.</p>