How to pass variable to a ViewController that is embedded in a Navigation Controller?

Question

I want to pass data from ViewController1 to ViewController2. ViewController2 is embedded within a Navigation Controller (because I have a Segmented Control that corresponds to 3 Child View Controllers). My segue is directly from ViewController1 to the Navigation Controller.

I tried the following in ViewController1:

ViewController2().testID = "test value"

With the following in ViewController2:

var testID = ""

However testID does not update when I run print(testID) in ViewController2.

What is recommended for passing data from ViewController1 to ViewController2? Any help/advice is much appreciated!

Answer 1

You can pass the value by overriding the prepare(for segue:) function in ViewController1

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

    // Get the new view controller using segue.destination 
    guard let destination = segue.destination as? UINavigationController else {
        return
    }

    guard let finalDestination = destination.viewControllers.first as? ViewController2 else {
        return
    }

    finalDestination.testID = "Test Value"
}