title: Print Double with two digits both before and after the decimal separator
body: <p>I'm trying to print a Double with this format : 01.87 or 23.98. </p>
  
  <p>I've found how to print only 2 digits after the point but I don't found how to print 2 digits before. </p>
  
  <p>This is my code for the moment:</p>
  
  <pre><code>let str = NSString(format: "%.2f", myValueToPrint as! Double)
  </code></pre>
  
  <p>How can I print my double like 00.00?</p>