Objective-C: What is .m?
This was a bit odd for me but I just got the answer I wanted.
When you create a class you create a .h (where applicable) and a .m. The .h is your interface. No sweat…seen these before. Hrmm…what does the “m” stand for though?
.m = implementation file
That makes sense. I mean I knew it was the @implementation code but I didn’t know what the “m” in the filename stood for.
Nothing mind-blowing…just blogging a note. 
May 15th, 2009 at 7:59 pm
Or you can think of it terms of object oriented encapsulation.
The .h file contains the public facing interface for your class; all the stuff that you expect folks using your code to see and understand.
The .m file contains all the implementation details of your class; all the stuff that you might change at a whim as long as it doesn’t change the meaning of something in the .h.
.m files can contain more than @implementations, they can contain private interfaces, too. And on the iPhone or 64 bit Mac OS X runtimes, they can implement private instance variables through class extensions and @synthesize.
May 19th, 2009 at 10:01 pm
@bbum
Good stuff. Thanks for providing more clarity.
I have a blog post coming up about @synthesize. It is interesting and I want to learn more about it.
May 28th, 2009 at 11:11 am
Thanks, good article.
June 9th, 2009 at 1:53 am
No sweat.
June 4th, 2009 at 11:37 am
It is 2009 and you are just now writing about objective C? Where have you been for the past several years.
June 9th, 2009 at 1:52 am
I’ve been living in about 4 other languages comfortably. Objective-C had 0 appeal until recently. Heck…I just bought my first Mac in October 09.