topic Re: reference macro from loop in SAS Programming

reference macro from loop

tom12122 — Thu, 31 May 2012 13:37:24 GMT

I have data step with DO i=1 to 5 loop.

I need to reference macro variable & Ti (&T1 for i=1, &T2 for i=2 etc.)

How to do that?

Alpay — Thu, 31 May 2012 13:51:49 GMT

You may use SYMGET to resolve the macro variable name at run time.

CATS() function will construct the name of the macro variable name as 'T1', 'T2', etc at run time.

SYMGET() function will get the value the macro variable produced by CATS() function (e.g., SYMGET('T1') when i=1).

Zafer

%let T1=A;

%let T2=B;

%let T3=C;

%let T4=D;

%let T5=E;

data _null_;

do i=1 to 5;

T = SYMGET(CATS('T',i));

put i= T=;

end;

run;

i=1 T=A

i=2 T=B

i=3 T=C

i=4 T=D

i=5 T=E

Linlin — Thu, 31 May 2012 14:07:11 GMT

%let t1=a1;
%let t2=a2;
%let t3=a3;
%let t4=a4;
%let t5=a5;

data want;
do i=1 to 5;
id=symget(cats('t',i));
output;
end;
run;
proc print;run;

Linlin

Tom — Thu, 31 May 2012 15:31:43 GMT

I am curious about why you would want a data step DO loop to reference a series of macro variables?

Wouldn't it be easier to restructure the code so that the macro variables are instead actual variables? Then you could use an array reference.