What is "#" doing/saying when it leads a line of code?

[wornhall]

In this code, for example, what is the effect of the "#" sign?

Public Function Exists(Key As Variant) As Boolean
#If Mac Or Not UseScriptingDictionaryIfAvailable Then
Exists = Not IsEmpty(dict_GetKeyValue(Key))
#Else
Exists = dict_pDictionary.Exists(Key)
#End If
End Function

I have searched high and low, and cannot find this information.

Thanks

 

[mikerickson]

That is conditional compilation.

If it is run on a Mac it will compile and execute

Exists = Not IsEmpty(dict_GetKeyValue(Key))

and ignore (and not even try to compile)

Exists = dict_pDictionary.Exists(Key)

otherwise, the reverse.

This protects computers from trying to compile code that they don't support. For example, this protects a PC from trying to compile the MacScript code, that it doesn't support.

#If Mac Then
    FolderPath = MacScript("choose folder")
#Else
    'FolderPath = (windows code that I don't know)
#End If

A simple IF will compile the code in both branches. Or at least try, and crash if that code isn't supported by the machine running the code.

Conditional Compliation will not compile the code in the un-run branch.

 

[Rick Rothstein]

To follow up on Mike's post, if you Google this...

vba conditional compilation

you will get a bunch of links where you can find out more information about it.

 

[wornhall]

Thank you both for the excellent replies. This answers my question(s).

Warren Hall