[interpol_p]

Indexed subscripting is available down to iOS 4.x I think — definitely available on iOS 5. It's a compiler technology, not related to the SDK.

[conradev]

No, declaring literals is a compiler technology that works with any SDK.

Subscripting requires runtime support in the form of `-[NSDictionary objectForKeyedSubscript:]` and pals , available only in iOS6 and above:

http://developer.apple.com/library/ios/documentation/cocoa/r...:

[interpol_p]

Thank you for the correction — I was thinking of ARC and weak references when I made that comment.

[conradev]

Actually, I stand corrected, indexed subscripting works back to iOS 5:

https://developer.apple.com/library/ios/#releasenotes/Object...