title: Using a variable to change the name of an image displayed in an UIImageView
body: <p>I'm a completely newbie to iOS and have been focussing on learning Swift. However I'm also dabbling in Objective-C.</p>
  
  <p>I can't seem to find a way of changing the image displayed on my app dependent on a data value I have in a variable. I have text value "5" for example that i want to put between a text prefix and suffix so that I can use that as the file name to display in a UIImageView.
  Ultimately I want to achieve "Prefix"+ variable + "suffix" into something I can pass to my image view. 
  So far I have this. </p>
  
  <pre><code> NSString *fileName = @"fhrs_";
  fileName = [fileName stringByAppendingFormat:@"%@", self.ratingVal];
  fileName = [fileName stringByAppendingFormat:@"_en-gb.jpg"];
  </code></pre>
  
  <p>when the code gets here "fileName holds the correct value for the file I want to display in the UIImageView.</p>
  
  <pre><code>vwImgRating.image = [UIImage imageNamed:@"%@", fileName];
  </code></pre>
  
  <p>However I get a message when trying to compile that " Too many arguments to method call, expected 1, have 2.
  Help!</p>