iOS App xcode build errors

Neither the original question nor the accepted answer note that the code with the error is generated code when a project is created and as such generally shouldn't need to be changed.

The problem is because of the version of Xcode. UIApplicationLaunchOptionsKey has been renamed to UIApplication.LaunchOptionsKey in the newer version of Xcode (10.2). I came across this when I tried to open my project in an older version of Xcode. This sucks because I now can't work on my project on my older computer that can't be updated to the latest version.

It should be like this :

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    return true
}