To preprocess or not to preprocess?

[gwsounddsg]

I am curious about the preprocessor and how the #define directive actually works.  Let's say I have something like this:

Code: (Objective-C)

 #define kTest (double) (4.0 * atan(1.0) * 0.5) 

When later in my code I use kTest, does it have to recalculate the value for kTest or does the preprocessor do the calculation and kTest is just passing the value?

GW
 

[gwsounddsg]

So after some research I found the answer to my question.  Using a  #define directive essentially inserts the code where the macro is located in your code.  So it would be better to do something like:

Code: (Objective-C)

 static double kTest (4.0 * atan(1.0) * 0.5); 

GW