title: Convert optional string to Int64
body: <p>I am trying to convert an optional string to a string and then to an Int64.</p>
  
  <pre><code> let number = blog["number"] as! String
  print(Int64(number))
  </code></pre>
  
  <p>The problem is that the "number" key is an optional string so it crashes when going to Int64. I have a couple methods to remove the optional type but none worked.</p>