I often want to provide a list of variables, say, to a macro and have it run for each of them, instead of cluttering up my code with several invocations of the same macro for each of the variables.
Suppose I want to run the macro for three variables, , and . I could say:
%calculate_means(ret); %calculate_means(retx); %calculate_means(shrout);
Or I could write a foreach macro:
%macro foreach(listofvariables); %let i=1; %do %while(%scan(&listofvariables, &i, ' ')>0); %let thevar=%scan(&listofvariables, &i, ' '); %put We have the variable &thevar; %calculate_means(&thevar); %let i=%eval(&i+1); %end; %mend;
And call it with
%foreach(ret retx shrout);