Detect current device with UI_USER_INTERFACE_IDIOM() in Swift

Question

What is the equivalent of UI_USER_INTERFACE_IDIOM() in Swift to detect between iPhone and iPad?

I get an Use of unresolved identifier error when compiling in Swift.

Answer 1

When working with Swift, you can use the enum UIUserInterfaceIdiom, defined as:

enum UIUserInterfaceIdiom : Int {
    case unspecified

    case phone // iPhone and iPod touch style UI
    case pad   // iPad style UI (also includes macOS Catalyst)
}

So you can use it as:

UIDevice.current.userInterfaceIdiom == .pad
UIDevice.current.userInterfaceIdiom == .phone
UIDevice.current.userInterfaceIdiom == .unspecified

Or with a Switch statement:

    switch UIDevice.current.userInterfaceIdiom {
    case .phone:
        // It's an iPhone
    case .pad:
        // It's an iPad (or macOS Catalyst)
    case .unspecified:
        // Uh, oh! What could it be?
    }

UI_USER_INTERFACE_IDIOM() is an Objective-C macro, which is defined as:

#define UI_USER_INTERFACE_IDIOM() \ ([[UIDevice currentDevice] respondsToSelector:@selector(userInterfaceIdiom)] ? \ [[UIDevice currentDevice] userInterfaceIdiom] : \ UIUserInterfaceIdiomPhone)

Also, note that even when working with Objective-C, the UI_USER_INTERFACE_IDIOM() macro is only required when targeting iOS 3.2 and below. When deploying to iOS 3.2 and up, you can use [UIDevice userInterfaceIdiom] directly.