Date:         Tue, 30 Aug 2005 12:22:29 -0400
Reply-To:     Jim Groeneveld <jim1stat@YAHOO.CO.UK>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Jim Groeneveld <jim1stat@YAHOO.CO.UK>
Subject:      Re: Best practice: check for blank macro parameters
Comments: To: M N <iced_phoenix_news@YAHOO.COM>

Hi Matt,

I mainly use something like:
%IF &MacroVar EQ %THEN ....... (or NE instead of EQ)

Surrounding quotes do not make sense as quotes in macro code; they are just
part of the character string.

So, if the macro variable to test legitimately may have contents at which
the macro program would crash, because of unintended interpretation of that
contents, I quote the macro variable (which is generally a better idea) as
in:
%IF %QUOTE(&MacroVar) EQ %THEN ....... (or NE instead of EQ)

Regards - Jim.
--
Y. (Jim) Groeneveld, MSc., Biostatistician, Vitatron b.v., NL
Jim.Groeneveld_AT_Vitatron.com (replace _AT_ by AT sign)
http://www.vitatron.com, http://home.hccnet.nl/jim.groeneveld

My computer always teaches me something new I thought I knew already.

[common disclaimer]

On Tue, 30 Aug 2005 08:59:49 -0700, m n <iced_phoenix_news@YAHOO.COM> wrote:

>Dear SAS-L,
>
>For the common practice of checking that required
>macro parameters are not blank, different programmers
>adopt different approaches:
>
>* %if &VAR= %then <insert code>
>* %if "&VAR"="" %then <insert code>
>* %if &VAR=%str() %then <insert code>
>* using %superq(), %nrstr, %bquote, %nrbquote, etc in
>various ways.
>
>Etc, etc.
>
>Is there any consensus among the gurus as to a Best
>Practice in this regard (i.e. a method that is quite
>likely to work regardless of what users may pass into
>the macro)?
>
>Thanks in advance,
>Matt
>
>
>
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