December 2013
Beginner
576 pages
16h 4m
English
Content preview from Programming in Objective-C, Sixth Edition
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The #undef Statement
Sometimes you need to cause a defined name to become undefined. You do this with the #undef statement. To remove the definition of a particular name, you write the following:
#undef name
Therefore, this statement removes the definition of IPAD:
#undef IPAD
Subsequent #ifdef IPAD or #if defined (IPAD) statements evaluate to FALSE.
This concludes our discussion on the preprocessor.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.