class FirstViewController: UIViewController, UITextViewDelegate {

    @IBOutlet weak var inputTextView: UITextView!
    @IBOutlet weak var textViewCountLabel: UILabel!



    // MARK: set maximum text.cout
    func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        let newText = textView.text
        let numberOfText = newText!.count

        if (range.length + range.location > numberOfText){
            return false
        }
        let newLength = numberOfText + text.count - range.length
        return newLength <= 10
    }

    // MARK: strat typeing with blank
    func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
        textView.text = ""
        let numberOfText = textView.text.count
        textViewCountLabel.text = "\(numberOfText)"
        return true
    }

    // MARK: show the text count on label
    func textViewDidChange(_ textView: UITextView) {
        let numberOfText = textView.text.count
        textViewCountLabel.text = "\(numberOfText)"
    }

    func textViewDidEndEditing(_ textView: UITextView) {
        let numberOfText = textView.text.count
        if numberOfText == 0 {
            textView.text = "input here"
        }
    }

    // MARK: set delegate
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        inputTextView.delegate = self
    }
}