问题
I just started to develop with with Xcode 4.2 and iOS5. After creating empty Tabbed application project, I have noticed that a new keyword "strong" is used on properties. I read on this post about it being related to retain replacement in ARC environment, but it's not the case because I didn't checked "Use Automatic Reference Counting" check box.
回答1:
The keyword "Strong" is a synonym for "retain" in non-ARC environments.
For ARC-envs read up here: http://clang.llvm.org/docs/AutomaticReferenceCounting.html#ownership.spelling.property
来源：https://stackoverflow.com/questions/7790407/why-a-keyword-strong-is-used-on-a-property-in-non-arc-environment