Intersection of two macro?

[braam]

I have two macro variables. Let's say the first includes A B C and the second includes A B D. Can I make the intersection of the two macro variables, which contains A and B?

[Kurt_Bremser · Accepted solution]

Scan iteratively through one macro variable and use findw into the second:

%let in1=A B C;
%let in2=A B D;

data _null_;
length result $10;
do i = 1 to countw("&in1.");
  if findw("&in2.",scan("&in1.",i)) then result = catx(' ',result,scan("&in1.",i));
end;
call symputx('result',result);
run;

%put &result.;