UITableView Refresh

class ExampleViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

    // assuming we've added a UITableView as a subview
    //  to our UIViewController in Storyboard and connected it
    @IBOutlet var tableView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.dataSource = self
        tableView.delegate = self

        // instantiate a UIRefreshControl
        let refreshControl = UIRefreshControl()
        // assign its target action
        refreshControl.addTarget(self, action: #selector(doRefresh(_:)), for: .valueChanged)
        // assign it to the tableView's .refreshControl property
        tableView.refreshControl = refreshControl

    }

    @objc func doRefresh(_ sender: Any?) -> Void {
        // do what we want for refreshing...
        //  here, we delay for 1-second to simulate getting new data
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {
            // get a reference to the Refresh Control that called this func
            guard let rc = sender as? UIRefreshControl else { return }
            // done refreshing
            rc.endRefreshing()
        })
    }

    // all the other normal tableView stuff
    // ...

}