title: NSString stringWithFormat adding a percent
body: <p>How can I add a percent to my stringWithFormat function? For example, I'd like to have the following:</p>
  
  <pre><code>float someFloat = 40.233f;
  NSString *str = [NSString stringWithFormat:@"%.02f%",someFloat];
  </code></pre>
  
  <p>This should cause the string to be:</p>
  
  <pre><code>40.23%
  </code></pre>
  
  <p>But it is not the case. How can I achieve this?</p>