Swift - How do you DECIDE the optimal “Deployment Target” for your iOS app

Question

On Xcode, you can decide the \"Deployment Target\" by yourself, but you may choose too old version to run the app stably since some of methods in your code are supported by late

Answer 1

Thats actually a new feature of Xcode 7 and Swift 2.0 see from swift website:

Swift Apple

On the website it states, under Availability

Swift 2.0 has built-in availability checking to make it easy to build the best possible app for each target OS version. The compiler will give you an error when using an API too new for your minimum target OS