How can I use a variable in another ViewController?

Using Swift
#1

Hi! I am creating a quiz. I need a variable for the number of questions the user chooses. I have linked the buttons that allow this to a ViewController. How can I make sure that I can use that variable in another ViewController (where the code is written for the questions)?

#2

If you’re storing questions in an array, the number of questions could be implied by the size of the array. Here is an example of that: https://github.com/vermont42/Conjugar/blob/master/Conjugar/Quiz.swift#L20

An instance of Quiz may be shared among view controllers.