title: Crash iterating through an array
body: <p>I'm trying to simply print out the contents of an array. </p>
  
  <pre><code>//initialization, ...
  
      NSArray *stockprices = [NSArray arrayWithObjects:@[stock1,stock2,stock3], nil];
  
      for (BNRStockHolding *stock in stockprices) {
  //            says that there are 3 objects in stock and crashes.
  //            tried to check -&gt; isMemberOfClass:BNRStockHolding in an if before and got 'unexpected interface name'.
          NSLog(@"Purchase Price: %.02f \n Shares: %d \n Current Price: %.02f \n \n \n \n", [stock purchasePrice], [stock numberOfShares],[stock currentSharePrice]);
  </code></pre>