Which swift version for iOS 7+

Question

I'm new to iOS development, trying to develop an application.

Once I've seen in these statistics that iOS 7 has a really small market share I decided to support iOS 7 or higher in a way to make an app to all iphone OS available in the market. I also decided to use swift as code language but not sure which swift version should I choose.

Which swift version should I choose for iOS 7 or higher development?

Answer 1

You have to use the latest swift version Swift 4.2

As iOS 12 is out now so you have to use iOS 10 and above because we should support recent 3 versions.

Images source

If you target iOS 10 and above then you hit the 95% users

Answer 2

The Swift application will work only on iOS 7+. The Xcode will add the Swift library to every build so, you can use any version of Swift language and all of them will work on all iOS starting from 7th. Apps created with Swift will run on iOS 7+ and Mac OS 10.9 +

so use the latest version always.

Answer 3

Apple states that

Starting July 2018, all iOS app updates submitted to the App Store must be built with the iOS 11 SDK and must support the Super Retina display of iPhone X.

(The same requirement for new apps started on April 2018.)

So, your choice are very few, Xcode 9 (with iOS 11 SDK) or Xcode 10 (with iOS 12 SDK). (I believe we should read the requirement as iOS11 SDK or later.)

And supporting iOS 7 with Xcode 9/10 is very difficult. (I do not know if it is possible or not.) Deployment Target does not accept versions less than 8.0 (*), and iOS 7 Simulators are not provided.

(*) Some versions of Xcode replaces versions less than 7.0 to 8.0, even if I entered the version number manually. And at least, both Xcode versions does not show 7.x in the popup menu of the Deployment Target.

I recommend you to use the latest released version of Xcode (10, which comes with Swift 4.2), and make your minimum supported version to iOS 8.0 or later.