reverse.swift

var testArray = [String]()
var initialLoad = true

override func viewDidLoad() {

    DataService.ds.REF_TITLE.observeEventType(.ChildAdded, withBlock: { snapshot in
    
       let lastName = snapshot.key as String
       self.testArray.insert(lastName, atIndex: 0)
    })
    
    DataService.ds.REF_TITLE.observeSingleEventOfType(.Value, withBlock: { snapshot in
        
        if self.initialLoad == true {
            self.tableView.reloadData()
            self.initialLoad = false
        }
    })
}

@IBAction func refreshBtn_clicked(sender: AnyObject) {

    tableView.setContentOffset(CGPointZero, animated: true)
    self.tableView.reloadData()
 }