PropertyObserver.swift

final class ViewController: UIViewController {
    let containerView = UIView()
    let tableView = UITableView()
    var dataModel: [String] = ["Jan", "Feb", "March"] {
        didSet {
            if (dataModel != oldValue) {
                tableView.reloadData()
            }
        }
        willSet(newValue) {
            // Set label text by this value
        }
    }
}