title: How to format phone number realtime (when using UITextfield) in iOS for different region codes?
body: <p>I found '<em>NBAsYouTypeFormatter</em>' and referred to the demo provided. But, I want phone number formatted dynamically when user entering phone number in UITextField. </p>
  
  <p>Remember, region code is not fixed to one or two country in my case e.g. only @"US" or only other. Region code will be selected by user from drop down and selected code will be passed by me by following line:</p>
  
  <pre><code>NBAsYouTypeFormatter *asYouTypeFormatter = [[NBAsYouTypeFormatter alloc] initWithRegionCode:@"US"];  // may be any other than 'US'
  NSString *output = [asYouTypeFormatter inputString:@"9999988888"];
  </code></pre>
  
  <p>Now, how would I be able to format number textfield dynamically when user types in number textfield?</p>