title: No exact matches in call to initializer error message in swift
body: <p>I'm confused. Could someone please tell me why I get a "No exact matches in call to initializer" error when I have this code....</p>
  
  <pre><code>    let bill = textField.text
      let billTotal = Double(bill)
  </code></pre>
  
  <p>but when I force unwrap textField.text the error goes away and everything is good...</p>
  
  <pre><code>    let bill = textField.text!
      let billTotal = Double(bill)
  </code></pre>
  
  <p>My thinking is that it should still work without force unwrapping but the app will crash if the textField is nil.  </p>
  
  <p>Also, why can I not use an optional instead of force unwrapping? </p>
  
  <pre><code> let bill = textField.text?
   let billTotal = Double(bill)
  </code></pre>
  
  <p>Using an optional gives me the same error: "No exact matches in call to initializer"</p>