>>>>>>#DEFINE's are string translations that take place at compile-time not run-time. That is, when PRG's etc. are converted into FXP's or EXE's etc.
>>>>>
>>>>>Houston,
>>>>>
>>>>>This isn't correct if the #DEFINE contains a function such as your INLIST() example. These are evaluated at run-time.
>>>>
>>>>George,
>>>>I just entered the following code into VFP6 SP3 running on NT4 SP6.

#DEFINE Sunday 1
>>>>#DEFINE Saturday 7
>>>>#DEFINE AWeekend   INLIST( iDayOfWeek, Saturday, Sunday )
>>>>
>>>>CLEAR
>>>>dCurrent = DATE()
>>>>iDayOfWeek = DOW( dCurrent )
>>>>IF (AWeekend) THEN
>>>>   ? "Yes it's a weekend."
>>>>ELSE
>>>>   ? "Not a weekend"
>>>>ENDIF

In my Edit, Preferences, I have 'Compile when saved' checked. After compiling the prg and running it for today (Monday), I get "Not a weekend", and then I changed the date to Sunday using my system clock and immediately ran the prg again (without any modifications and/or recompiling) - as expected the message changed to "Yes it's a weekend."
>>>>
>>>>If the INLIST() is 'evaluated' at compile-time, why does the message change?
>>>
>>>Houston,
>>>
>>>This is what you said,
>>>
>>>"#DEFINE's are string translations that take place at compile-time not run-time. That is, when PRG's etc. are converted into FXP's or EXE's etc."
>>>
>>>What I am saying is that if the #DEFINE contains a function call such as INLIST() this statement is not correct. These are dynamic and evaluate differently at run-time.
>>
>>Hi George,
>>I'd appreciate (and I'm sure a whole bunch of lurkers would also appreciate) a piece of code that demonstrates the 'evaluate differently at run-time'.
>
>
>Sure, try this:

#DEFINE DEFAULT_DIR SYS(5) + SYS(2003)

in a header file. Compile the application and drop it into a directory other than the compiled directory. It will display the current default directory, not the one that the application was compiled in.
>
>This discussion has occurred a couple of times in the past, BTW.

George,
I just entered your example into a prg.

#DEFINE DEFAULT_DIR SYS(5) + SYS(2003)
CLEAR
? DEFAULT_DIR
? SYS(5) + SYS(2003)

As expected, both lines return the same value - i.e. they are both evaluated at run-time not compile-time. I re-assert that the pre-processor in the VFP compiler does not evaluate anything at compile-time. All that is happening is the strings are swapped by the compiler before tokenization!