title: Regex with single quote (') not validating single quote
body: <p>I'm using following regex to validate name:</p>
  
  <blockquote>
    <p>^[a-zA-Z]{1}[a-zA-Z.' ]{1,20}$</p>
  </blockquote>
  
  <p>Single quote is mentioned in the second range. However, when I validate a string against this regex, single quote (') invalidates the match. Here's my code:</p>
  
  <pre><code>let nameRegEx = "^[a-zA-Z]{1}[a-zA-Z.' ]{1,21}$"
  let nameTest = NSPredicate(format:"SELF MATCHES %@", nameRegEx)
  let isNameValid = nameTest.evaluate(with: name)
  </code></pre>
  
  <p>I've tried <code>\'</code> but no use. </p>