SAS - How to return a value from a SAS macro?

Question

I would like to return a value from a SAS macro I created but I'm not sure how. The macro computes the number of observations in a dataset. I want the number of observations to be returned. %macro nobs(library_name, table_name); proc sql noprint; select nlobs into :nobs from dictionary.tables where libname = UPCASE(&library_name) and memname = UPCASE(&table_name); quit; *return nobs macro variable; &nobs %mend; %let num_of_observations = %nobs('work', 'patients'); Also, I would like the `&nobs` macro variable that is used within the macro to be local to that macro and not global. How can I do that?

Answer 1

Here's one solution. It keeps NOBS local but NUM_OF_OBSERVATIONS must be global to be of any use in subsequent steps of the program.

%macro nobs(library_name, table_name);

%local nobs;

data _null_;

set &library_name..&table_name(obs=1) nobs=tot_obs; /* note: NOBS= is a SAS option and isn't related to the macro variable nobs of same name */

/*return nobs macro variable; &nobs*/

call symputx('nobs', tot_obs);

run;

%let num_of_observations=&nobs.;

%mend nobs;

%nobs(work, patients); /* get num_of_observations */