title: forcing a number to be displayed with 2 decimal places using swift
body: <p>I have a lot of code very similar to this.</p>
  
  <pre><code>//Gross Total
      var gt:Float64 = tp01 + tp02 + tp03 + tp04 + tp05 + tat + ntat
      GrossTotal.text = "\(gt)"
  </code></pre>
  
  <p>Where I display numbers in a label. This code works fine. I would like to know how to force the number being displayed to always have a value with exactly 2 decimal places. Please only swift code. thank you</p>