Best way to define private methods for a class in Objective-C

I just started programming Objective-C and, having a background in Java, wonder how people writing Objective-C programs deal with private methods.

I understand there may be several conventions and habits and think about this question as an aggregator of the best techniques people use dealing with private methods in Objective-C.

Please include an argument for your approach when posting it. Why is it good? Which drawbacks does it have (that you know of) and how you deal with them?


As for my findings so far.

It is possible to use categories [e.g. MyClass (Private)] defined in MyClass.m file to group private methods.

This approach has 2 issues:

  1. Xcode (and compiler?) does not check if you define all methods in private category in corresponding @implementation block
  2. You have to put @interface declaring your private category in the begin of MyClass.m file, otherwise Xcode complains with a message like “self may not respond to message “privateFoo”.

The first issue can be worked around with empty category [e.g. MyClass ()].
The second one bothers me a lot. I’d like to see private methods implemented (and defined) near the end of the file; I do not know if that’s possible.

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