title: Argument in message expression is an uninitialized value
body: <p>The code works correctly, but I am getting the warning <em>"Argument in message expression is an initialized value"</em> for this piece of code:</p>
  
  <pre><code>    NSString *quality;
      switch(theItem.quality) {
          case 1:
              quality = @"UNDEF, Set it up!";
              break;
          case 2:
              quality = @"G, (Good)";
              break;
          case 3:
              quality = @"VG, (Very Good)";
              break;
          case 4:
              quality = @"F, (Fine)";
              break;
          case 5:
              quality = @"VF, (Very Fine)";
              break;
          case 6:
              quality = @"XF, (Extra Fine)";
              break;
          case 7:
              quality = @"UNC, (Uncirculated)";
              break;
          case 8:
              quality = @"PROOF, (Proof)";
              break;
      }
  
      str = [NSString stringWithFormat:@"%@", quality];
  </code></pre>
  
  <p>Is it some issue or it's nothing and I can ignore it?
  Also, is it ok to initialize NSString this way -> <code>NSString *quality;</code>?</p>