iphone - Targeting iOS version, and which features will be available

Question

I am learning iOS development. And I had couple of questions, hope people don't mind answering them here.

I was reading a chapter about ARC in a book. It seems nice. I've heard it is for iOS 5. Now, my question is, if I want my app to be available for iOS4 - does it mean I can't use ARC? (that would be a shame).

Also, I am not sure yet, for which version of iOS I should target my app. How is this reflected on my code? For example, I suppose if I target iOS5 I can't use features of iOS6 right? But if I target iOS6, then my app won't run on iOS4? Any tips in this direction appreciated.

Answer 1

iOS 5 以降では ARC を使用できますが、IOS4 では使用できません。

アプリのターゲットを IOS 5 にする場合は、ARC も使用できます。iOS 5 をターゲットにすると、IOS 6 でも動作します (非推奨の機能のみが iOS 6 では動作しません)。