Do Xcode 8 Swift 3 apps run on iOS 7 successfully?

Question

Do Xcode 8 Swift 3 apps run on iOS 7 successfully?

I\'ve tried to determine this running a few tests described below, but can an expert with a better understanding o

Answer 1

I would hesitate to draw too many conclusions from your empirical tests. Specifically, I would not assume just because you got it to run on iOS 7 that it is guaranteed to work on iOS 7. They appear to only be guaranteeing iOS 8+ support.

As an aside, Apple generally suggests supporting only one iOS version back, anyway. And, as of May 9th, only 5% of devices are running iOS 7 or earlier (and this is likely to be further reduced by the time iOS 10 is released).

Answer 2

Do Xcode 8 Swift 3 apps run on iOS 7 successfully?

See Swift 3 iOS compatibility. Guaranteed iOS 8 support, unsure about iOS 7. See this answer on Swift 2 and iOS 7. The last comment states that Apple probably doesn't want you targeting iOS 7 anyways. If it doesn't work, it's probably not Swift that's the issue, but Xcode that is saying no.

What can I make of all the testing outcomes in the table above?

I'm not sure what you mean here.

Importantly, when it comes time to distributing the app through the App Store created in Xcode 8 with Swift 3, is it safe to expect that the app, which installed successfully via iTunes on an iOS 7.1.2 iPhone device, will still be compatible for all iOS 7 devices when downloaded at the App Store?

It's probably never safe to expect anything in which you are trying to work around Xcode.

Xcode 7.3.1 allows devices from iOS 7 through to iOS 9 for testing and debugging while in development?

And? Xcode 8 doesn't. iOS 7 through iOS 9 is two versions, iOS 8 through iOS 10 is two versions.

What is the point of Swift 2.3 as an intermediate step to Swift 3?

Because Swift 3 is such a major jump from Swift 2.2, they provide Swift 2.3 if you aren't ready to go to Swift 3 yet. However, they recommend going to Swift 3. Swift 3 also allows you to access some new features.