Register multiple value types in UserDefaults with Swift 3

Question

I am converting an old Swift 2 project to Swift 3. In the previous version I registered default values for unset user defaults in the AppDelegate like this:

let defaults = NSUserDefaults.standardUserDefaults()
let defaultValues = [
    "stringKey" : "",
    "intKey" : 50
]
defaults.registerDefaults(defaultValues as! [String : AnyObject])

Xcode was helping to convert it, but the autoconvert in Xcode wasn't working for the following error:

Heterogenous collection literal could only be inferred to '[String : Any]'; add explicit type annotation if this is intentional

The auto correct finally did work, but by that time I had written most of this question so I will just add the answer below rather than deleting the question. (Also, the auto convert suggestions were more wordy than the answer I am providing below.)

Notes

• Here is an answer for registering a single type in Swift 3.
• I am talking about registering, not setting, multiple default values.

Answer 1

Here is the syntax for Swift 3. I am including it in its context in the AppDelegate.

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    override init() {
        let defaults = UserDefaults.standard
        let defaultValues : [String : Any] = [
            "stringKey" : "",
            "intKey" : 50
        ]
        defaults.register(defaults: defaultValues)
        super.init()
    }

    // ...
}

Remember that this does not set the values, it only provides some initial defaults for when the user has not yet set them.