title: iPhone SDK: Check validity of URLs with NSURL not working?
body: <p>I'm trying to check if a given URL is valid and i'm doing it like this:</p>
  
  <pre><code>- (BOOL)urlIsValid:(NSString *)address {
      NSURL *testURL = [NSURL URLWithString:address];
      if (testURL == nil) {
          return NO;
      }
      else {
          return YES;
      }
  }
  </code></pre>
  
  <p>Since "URLWithString" is supposed to return "nil" if the URL is malformed I thought this would work but it doesn't for some reason. Could someone please tell me why?
  Thanks in advance!</p>