Passing data between view controllers from a UITabBarController stack using Swift

Let us have two UIViewController classes named viewController1 and viewController2 in our UITabBarController stack and have them as VC1 and VC2 respectively

var VC1: viewController1 = viewController1.alloc()
var VC2: viewController2 = viewController2.alloc()

Let us also have a UITabBarController class named TabBarController and name them tBc

var tBc: TabBarController = TabBarController.alloc()

Then let us contain them in that UITabBarController

tBc.viewControllers = [VC1,VC2]

That is what we need for our Application delegate or something that will initialise our TabBarController

Assuming we have a UILabel named "myLabel" on VC2, let us say we wish to pass data from VC1 to the UILabel on VC2. We would then have this on VC1 to do it:

var vcArray = self.tabBarController?.viewControllers as NSArray!

This would fetch the view controllers in the tabbarcontroller's stack and list them in an array. Then make next UIViewController known on VC1 and name it nextVC:

       var VC2: UIViewController = vcArray.objectAtIndex(1) as UIViewController
       var nextVC = VC2 as viewController2

Then you could now pass data on the next viewcontroller like having this on VC1:

       nextVC.myLabel.text = "This will appear on the next view"