if and &if

[tomer]

hi everyone,
what the difference between if and &if , message and &message (and so on..)?
When should you use & prefix ?


Thanks in advance!

 

[RealHeavyDude]

&if and the like are a pre-processor directives which get resolved at compile time. They are not executable statements which get executed at run time.

Where as if and the like are executable statements that get executed at run time.

With pre-precessores you can for example make decisions at compile time so that parts of your code are only compiled when certain rules are true.

Heavy Regards, RealHeavyDude.

 

[tomer]

Thank's

 

[RealHeavyDude]

I should have included in my respons that pre-precessore directives should not be confused with pre-processor variables {&myvar} or the include technique {myfile.i}.

Heavy Regards, RealHeavyDude.

 

[tamhas]

BTW, some of us think preprocessor directives are evil because they make it difficult to analyze code.