How to do a live UITextField count while typing (Swift)?

Question

I would like to count the character when user keep typing in UITextField with swift.

Image of Field and Label:

Answer 1

For multiple UITextView

class ViewController: UIViewController, UITextViewDelegate {

 @IBOutlet weak var ticketSummaryTV: UITextView!
 @IBOutlet weak var ticketDescriptionTV: UITextView!

 @IBOutlet weak var summaryCountLbl: UILabel!
 @IBOutlet weak var descriptionCountLbl: UILabel!

 override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.

    ticketSummaryTV.delegate = self
    ticketDescriptionTV.delegate = self

    self.updateCharacterCount()
 }

 func updateCharacterCount() {
    let summaryCount = self.ticketSummaryTV.text.characters.count
    let descriptionCount = self.ticketDescriptionTV.text.characters.count

    self.summaryCountLbl.text = "\((0) + summaryCount)/50"

    self.descriptionCountLbl.text = "\((0) + descriptionCount)/500"
 }

 func textViewDidChange(_ textView: UITextView) {
    self.updateCharacterCount()
 }


 func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool{
    if(textView == ticketSummaryTV){
       return textView.text.characters.count +  (text.characters.count - range.length) <= 50
    }else if(textView == ticketDescriptionTV){
        return textView.text.characters.count +  (text.characters.count - range.length) <= 500
    }
    return false
 }
}