topic parameter in macros in SAS Programming

parameter in macros

SAS_inquisitive — Fri, 26 Jul 2019 20:29:54 GMT

Hello,

Is it legal to use same parameter in both outer and inner macro here?

%macro inner (ds = );
	proc print data = &ds.;
	run;
%mend;

%macro outer (ds =);
	%inner(ds = &ds.);
%mend outer;
%outer (ds = sashelp.class)

Re: parameter in macros

Astounding — Fri, 26 Jul 2019 20:31:46 GMT

It is legal.

It should be avoided unless absolutely necessary. It becomes difficult to tell what &DS refers to, since the values in the inner and outer macros do not have to match.

Re: parameter in macros

Reeza — Fri, 26 Jul 2019 20:33:03 GMT

It's legal, but not a good idea.

Re: parameter in macros

SAS_inquisitive — Fri, 26 Jul 2019 20:43:50 GMT

@Astounding @Reeza . Thanks. In my case the macro variable value is same in both outer and inner. I want to add the extra parameter in outer macro for further processing.

Re: parameter in macros

Tom — Fri, 26 Jul 2019 20:46:39 GMT

Yes.

Not sure why some are saying it is not desirable. Use the same name if it makes the code easier to understand, or use different names if that makes more sense.

Re: parameter in macros

Astounding — Fri, 26 Jul 2019 20:47:13 GMT

You'll be fine. Do you understand the results that this variation would create?

%macro inner (ds = );
	proc print data = &ds.;
	run;
        %let ds = temp;
        %put Inner DS is &DS;
%mend;

%macro outer (ds =);
	%inner(ds = &ds.);
        %put outer DS is &DS;
%mend outer;
%outer (ds = sashelp.class)

Re: parameter in macros

SAS_inquisitive — Fri, 26 Jul 2019 20:56:48 GMT

@Astounding, You are overriding the name of macro variable &ds in inner macro.

Re: parameter in macros

Astounding — Fri, 26 Jul 2019 21:01:43 GMT

Yes, while the value in the outer macro remains unchanged.

You'll be fine with what you are planning.