NSUserDefaults - How to tell if a key exists

Question

I\'m working on a small iPhone app, and I am using NSUserDefaults as my data persistence. It only has to keep track of a few things, such as some names and som

Answer 1

In Swift3, I have used in this way

var hasAddedGeofencesAtleastOnce: Bool {
    get {
        return UserDefaults.standard.object(forKey: "hasAddedGeofencesAtleastOnce") != nil
    }
}

The answer is great if you are to use that multiple times.

I hope it helps :)