Objective c how to define macros

How in Objective c is defined as the following macro code:
# Ifdef _DEBUG
NSLog (@ "Error");
# Endif
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Nobody knows? This score how do I?
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cited a floor sqzxcv reply:

Nobody knows? This score how do I?

Not used, huh over a period of time to learn OC, only Bangding.
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The reply was deleted at the moderator 2010-04-22 13:21:39

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cited landlord sqzxcv reply:

how the following code in Objective c is defined as a macro:
# Ifdef _DEBUG
NSLog (@ "Error");
# Endif

Accordance with the standard C syntax is no problem
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iPhone is deserted, said plate
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You then write it on the line ah?
That you are not already a pre-compiled it?
Zayang want?

Perhaps think so?

 
# Ifdef _DEBUG 
# Define TRACE (...) NSLog (__VA_ARGS__) 
# Else 
# Define TRACE (...) (void) 0 
# Endif 

In this way, you just call later on TRACE on the line, do not write in every place three sentences, Ha ha ha.
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According to the standard C syntax rules is possible!
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Like you are OK, ah, what the problem
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Is the same as with C, OBJECTIVE-C is an extension c
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references, 5th Floor defonds reply:

iPhone plate is deserted, said

Oh yes ah, too deserted
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If you are referring to how the development environment set Predefinition then please refer to this
http://blog.csdn.net/cloudhsu/archive/2010 / 07/26/5766100.aspx

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You are right.
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The reply was deleted at the moderator 2010-09-02 11:23:09

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You are right.
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Right way to go. .
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Like standard C
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This is not what your landlord pre-compiled is ah? Halo. . . .
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The reply was deleted at the moderator 2011-04-11 08:35:56

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cited landlord sqzxcv reply:

how the following code in Objective c is defined as a macro:
# Ifdef _DEBUG
NSLog (@ "Error");
# Endif

Macro code is replaced with ObjC okay.
If you want to customize a name, for example: # ifdef XXXXXX, defined in the project settings in a can.
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Can be used define SOME
#
It does not seem to support conditional compilation.
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cited 20 floor ilysony reply:

can use # define SOME

It does not seem to support conditional compilation.

Support.
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Look a little Mongolian, NSlog not that used in xcode in it?
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cited 22 floor dxchenqing reply:

look a little Mongolian, NSlog not that used in xcode in it?

The same question is a printf do not ......
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Macro which can not contain non-string symbol #
againThis situation can not be achieved landlord