Objective C, Difference between defining private variables with @private and defining them with class extension?

Question

I wonder the difference between defining private variables in the .h file using the key word @private and defining them in the .m file using the class extension?

Thanks.

Answer 1

iVar declared in the implementation are implicitly hidden (effectively private) and the visibility cannot be changed - @public, @protected and @private do not produce compiler errors (with the current Clang at least) but are ignored.