what is the difference between strong (in LLVM) and retain( in GCC)?

Question

strong（在LLVM编译器中）和retain（在GCC编译器中）之间有什么区别？

Answer 1

strong is a new feature in iOS 5 Automatic Reference Counting (ARC) which behave the same as retain in iOS 4. Referenced Article.

Also, check out this other SO question: @property definitions with ARC: strong or retain?

Answer 2

strong is a new keyword that was introduced along with arc (automatic reference counting). There are a bazillion articles about it if you search google, including this one http://cupsofcocoa.com/2011/11/27/the-jungle-part-4-automatic-reference-counting/