Date:         Fri, 19 Oct 2007 11:31:24 +0100
Reply-To:     Guido T <cymraegerict@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Guido T <cymraegerict@GMAIL.COM>
Subject:      Re: positional macro parameter as keyword
Comments: To: "ckxplus@yahoo.com" <ckxplus@yahoo.com>
In-Reply-To:  <1192787192.450004.173400@y27g2000pre.googlegroups.com>
Content-Type: text/plain; charset=ISO-8859-1

Hi,

Something similar used to be in the "gotcha" test we did for SAS programmer
interviews.

Given the following code ...

%macro m(x);
%put &x.;
%mend;

%m(a);
%m(x=b);
%m(x=b=c);
What would you expect to see in the log ...

1    %macro m(x);
2    %put &x.;
3    %mend;
4
5    %m(a);
*a
*6    %m(x=b);
*b
*7    %m(x=b=c);
*b=c
*
Not a very useful test :)

++ Guido

On 19/10/2007, ckxplus@yahoo.com <ckxplus@yahoo.com> wrote:
>
> It's more than 20 years ago since I wrote my first macro. But today I
> (inadvertently) discovered that you can refer to a positional
> parameter as a keyword, provided you use the right name. For example:
>
> %macro test(data);
>        %put data=&data;
> %mend;
>
> %test(demo);
> %test(data=demo);
>
> This prints 'demo' to the log in both cases. Could be a useful feature
> sometimes. Am I the only one in the dark about this feature?
>
> John Hendrickx
>