screen
The screen to display the window on.
Declaration
var screen: UIScreen { get set }Discussion
By default, UIKit sets this property to the primary device screen. If additional screens are attached to the device, you can assign a different screen object to display the window on that screen. A window is always displayed on only one screen.
Moving windows from screen to screen is a relatively expensive operation and isn’t optimal in performance-sensitive code. Instead, change the screen before displaying the window the first time. Changing the screen of a window that hasn’t been ordered onto the screen has no significant additional cost.