title: When to use enumerateObjectsUsingBlock vs. for
body: <p>Besides the obvious differences:</p>
  
  <ul>
  <li>Use <code>enumerateObjectsUsingBlock</code> when you need both the index and the object</li>
  <li><s>Don't use <code>enumerateObjectsUsingBlock</code> when you need to modify local variables</s> (I was wrong about this, see bbum's answer)</li>
  </ul>
  
  <p>Is <code>enumerateObjectsUsingBlock</code> generally considered better or worse when <code>for (id obj in myArray)</code> would also work? What are the advantages/disadvantages (for example is it more or less performant)?</p>