title: NSNumber? to a value of type String? in CoreData
body: <p>So I can't figure this out, am I supposed to change the '.text' to something else or do I have to go about converting the string into a double?</p>
  
  <p>Here is the code</p>
  
  <pre><code>if item != nil {
      // the errors I keep getting for each one is
      unitCost.text = item?.unitCost //cannot assign to a value 'NSNumber?' to a value of type 'String?'
      total.text = item?.total  //cannot assign to a value 'NSNumber?' to a value of type 'String?'
      date.text = item?.date //cannot assign to a value 'NSDate?' to a value of type 'String?'
  }
  </code></pre>