Swift pass data through navigation controller

Override prepareForSegue and set whatever value on the tableview you'd like. You can grab the tableview from the UINavigation viewControllers property.

override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!){

   let navVC = segue.destinationViewController as UINavigationController

   let tableVC = navVC.viewControllers.first as YourTableViewControllerClass

   tableVC.yourTableViewArray = localArrayValue   
}

For Swift 3 :

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

   let navVC = segue.destination as? UINavigationController

   let tableVC = navVC?.viewControllers.first as! YourTableViewControllerClass

   tableVC.yourTableViewArray = localArrayValue   
}

@Tommy Devoy's answer is correct but here is the same thing in swift 3

Updated Swift 3

  // MARK: - Navigation

//In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.


    if segue.identifier == "yourSegueIdentifier"  {

        if let navController = segue.destination as? UINavigationController {

            if let chidVC = navController.topViewController as? YourViewController {
                 //TODO: access here chid VC  like childVC.yourTableViewArray = localArrayValue 


            }

        }

    }

}

I was getting this error to Horatio's solution.

ERROR: Value of type 'UINavigationController' has no member 'yourTableViewArray'

So this might help others like me looking for a code only solution. I wanted to redirect to a Navigation controller, yet pass data to root view controller within that Nav Controller.

if let controller = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "yourNavigationControllerID") as? UINavigationController,
   let yourViewController = controller.viewControllers.first as? YourViewController {
        yourViewController.yourVariableName = "value"
        self.window?.rootViewController = controller  // if presented from AppDelegate
        // present(controller, animated: true, completion: nil) // if presented from ViewController
}