Step5.swift

@objc func keyBoardWillShow(notification: Notification) {
        if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            withAnimation {
               currentHeight = keyboardSize.height
            }
        }
    }

@objc func keyBoardWillHide(notification: Notification) {
        withAnimation {
           currentHeight = 0
        }
    }