Date:         Fri, 14 May 2010 01:21:10 -0400
Reply-To:     Søren Lassen <s.lassen@POST.TELE.DK>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Søren Lassen <s.lassen@POST.TELE.DK>
Subject:      Re: splitting terms from one macro argument
Comments: To: Jason Schoeneberger <jschoeneberger@CAROLINA.RR.COM>
Content-Type: text/plain; charset=ISO-8859-1

Jason,
What you are trying to do is what some people call macro "arrays".
The trick is to create the subject variables on the fly:

%macro test(subjects);
%local i n w;

%do i=1 %to 9999;
  %let w=%scan(&subjects,&i);
  %if %length(&w)=0 %then %goto endscan;
  %local subject&i;
  %let subject&i=&w;
  %end;
%endscan:
%let n=&i-1;

%do i=1 %to &n;
  %put subject&i=&&subject&i;
  %end;
%mend;

The trick is to use &&subject&i when refering to the macro variable.
It works because the macro processor does several passes,
in the first pass "&&" is translated to "&" while "&i" is translated
to a number, say 2. In the second pass we have "&subject2", which
gets translated to "math" or whatever.

Regards,
Søren

On Thu, 13 May 2010 07:09:29 -0400, Jason Schoeneberger
<jschoeneberger@CAROLINA.RR.COM> wrote:

>Hi,
>
>
>
>I'm putting together a macro and would like to include a parameter where
the
>user can list multiple subjects separated by a space (e.g read math
>science). There will, of course, be different numbers of terms depending on
>the user's needs, so I need to be able to identify the number of parameters
>submitted.  Further, I need to be able to run a piece of code separately
for
>each one of the subjects, so I'd like to be able to split them out into
>separate pieces with their own term.
>
>
>
>So in the example above, I would know that it has three subjects and then
>I'd like to be able to do something like this:
>
>
>
>%let sub1=read;
>
>%let sub2=math;
>
>%let sub3=science;
>
>
>
>I've followed some threads on the listserv already, but can't quite figure
>out how to make it work.  I've pulled together the following code, but to
no
>avail:
>
>
>
>%let i=1;
>
>%do %until (%qscan(&subjects,&i,%str( ))= %str());
>
>%let sub=(%qscan(&subjects,&i,%str( ));
>
>%put &sub;
>
>%let i=%eval(&i+1);
>
>%end;
>
>
>
>Any direction is appreciated.
>
>
>
>Jason