Technology Tales

Using NOT IN operator type functionality in SAS Macro

9th November 2018

For as long as I have been programming with SAS, there has been the ability to test if a variable does or does not have one value from a list of values in data step IF clauses or WHERE clauses in both data step and most if not all procedures. It was only within the last decade that its Macro language got similar functionality with one caveat that I recently uncovered: you cannot have a NOT IN construct. To get that, you need to go about things in a different way.

In the example below, you see the NOT operator being placed before the IN operator component that is enclosed in parentheses. If this is not done, SAS produces the error messages that caused me to look at SAS Usage Note 31322. Once I followed that approach, I was able to do what I wanted without resorting to older more long-winded coding practices.

options minoperator;

%macro inop(x);

%if not (&x in (a b c)) %then %do;
%put Value is not included;
%end;
%else %do;
%put Value is included;
%end;

%mend inop;

%inop(a);

Running the above code should produce a similar result to another featured on here in another post but the logic is reversed. There are times when such an approach is needed. One is where a small number of possibilities is to be excluded from a larger number of possibilities. Programming often involves more inventive thinking and this may be one of those.