title: How to append a string to NSMutableString
body: <p>i'm an absolute newbie with objective-c</p>
  
  <p>with this code</p>
  
  <pre><code>NSMutableString *teststring;
  [teststring appendString:@"hey"];
  NSLog(teststring);
  </code></pre>
  
  <p>nothing gets displayed in the console.</p>
  
  <p>Surely i'm doing something wrong here... :-)</p>