What's the rule of method declare in Obj-c? Could I use a method without declaration directly?

Question

In Xcode4.4, I found I can use a method define in .m file directly without declaration in .h head file or .m file.

what's the rule of method declaration in Obj-c? Could I use a method without declaration in head file?

Answer 1

If you declare a method in the header file, then other classes will be able to access that method.