title: arc4random and % operator
body: <p>I have a question about the arc4random() function in Objective-C.</p>
  
  <p>In the examples I have seen online, there is a <code>%</code> symbol right after the function call.  I think of <code>%</code> as the modulus operator, so does this symbol have another meaning when used after <code>arc4random()</code>?  How does it work?</p>