In Objective-C, does the binding of method really happen at “run-time”?

Question

I heard that Objective-C is influenced by the \"message passing mechanism\" of SmallTalk.

Objective-C, like Smalltalk, can use dynamic typing: an object

Answer 1

I figured out the reason finally..

It throw errors during compiling because -Werror flag is included, which will turn warning into error..

http://clang.llvm.org/docs/UsersManual.html#cmdoption-Werror

After I delete -Werror flag, everything works as expected and the error only happens at run-time.