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whats the difference between if/else and #if/#else
Posted: Tue Jul 16, 2013 1:09 pm
by Smotz
More of a general programming question, but:
whats the difference between if/else and #if/#else ?
Re: whats the difference between if/else and #if/#else
Posted: Tue Jul 16, 2013 1:29 pm
by lnevo
Its really #ifdef and #endif
These are pre-processing declarations that are used by the compiler vs actual c/c++ code that gets compiled.
So. #define x y
Replaces all occurance of x with y
Whereas
int x=y; is in code and uses a variable which takes up memory, the #define gets replaced before the compiler and so isnt a variable.
Essentially a lot of the #ifdef you see is aimed at making the ino smaller by only including code that is used.
Not sure how much that helps but maybe gets you started
Re: whats the difference between if/else and #if/#else
Posted: Wed Jul 17, 2013 1:43 pm
by Smotz
lol, thx. I was curious.