Making some code only run once

Question

I have some code that I would like to run only once in my MainViewController. It should run every time the user starts the app, but only after the MainViewController has loa

Answer 1

With Swift2.0, Xcode 7.0

var token: dispatch_once_t = 0

override func viewDidLoad() {
    super. viewDidLoad()
    dispatch_once(&token) {
        println("This is printed only on the first call to test()")
    }
    println("This is printed for each call to test()")
}