UIApplicationLaunchOptionsKey not found

Question

UIApplicationDelegate method - application(_:didFinishLaunchingWithOptions:) showing an error with Swift 4.2 (Xcode 10).

UIApplicationLaunchOptionsKey not found

What is replacement of UIApplicationLaunchOptionsKey in Swift 4.2?

Answer 1

'UIApplicationLaunchOptionsKey' has been renamed to 'UIApplication.LaunchOptionsKey'. Replace 'UIApplicationLaunchOptionsKey' with 'UIApplication.LaunchOptionsKey'.

Click on error hint, will show you solution:

Answer 2

func application(_ application: UIApplication, 
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {

}

Answer 3

Xcode would fix-it but UIApplicationLaunchOptionsKey is replaced by a nested type UIApplication.LaunchOptionsKey.

Answer 4

It should be UIApplication.LaunchOptionsKey, Please find following apple documentation

Answer 5

I have tried the below snippet of the code and worked for me.

func application(_ application: UIApplication, 
    didFinishLaunchingWithOptions launchOptions: [UIApplication: Any]? = nil) -> Bool {

}

Just provide UIApplication in launchOptions. Hopes it will work for you as well. :)