title: Most efficient way to iterate over all the chars in an NSString
body: <p>What's the best way to iterate over all the chars in an NSString? Would you want to loop over the length of the string and use the method.</p>
  
  <pre><code>[aNSString characterAtIndex:index];
  </code></pre>
  
  <p>or would you want to user a char buffer based on the NSString?</p>