I cannot get my Swift 3 Timer to fire

Question

I have used timers before and they worked, but ever since NSTimer changed to Timer, my timers refuse to work. The code I have tried is as follows:

override func viewDidLoad() {
    super.viewDidLoad()

    _ = Timer(timeInterval: 3, target: self, selector: #selector(test), userInfo: nil, repeats: true)

}

func test() {
    print("The timer worked")
}

The test function is never called and I have no idea why. I have also tried initializing it first and using it like so:

var followUpTimer:Timer!

override func viewDidLoad() {
    super.viewDidLoad()

    followUpTimer = Timer(timeInterval: 3, target: self, selector: #selector(test), userInfo: nil, repeats: true)

}

func test() {
    print("The timer worked")
}

But that does not work either. What am I doing wrong? All the answers I find online show that this is the correct way of doing it.

Answer 1

(NS)Timer needs a run loop to work properly. You can add the timer programmatically to the loop but it's more convenient to use the method

Timer.scheduledTimer(withTimeInterval:...