topic Re: Looping through macros in SAS Programming

Looping through macros

yashij2138 — Thu, 20 Jun 2019 18:20:51 GMT

I want to make a union of all datasets from 2010-2019 whcih are named like students_201001, students_201002....students_201012.....students_201905.

I was using a nested loop one for year and other for moth, but it is not working:

%macro join;
%Do i=2010 %to 2019;
%DO j=01 %TO 12;
data append_recov_&i&j;
set chi_perf.perf_chi_&i
run;
%end;
%end;
%mend;
%join;

Please help!

Kurt_Bremser — Thu, 20 Jun 2019 18:30:08 GMT

There's a much simpler way by using wildcards:

data want;
set students_201:;
run;

Tom — Thu, 20 Jun 2019 18:46:34 GMT

The iterative %DO loop will convert your values into numbers and then back to strings to assign to the loop variable.

So %DO j=01 %to 12 will set J to 1,2,3,4,5,6,7,8,9,10,11,12.

If you want to convert the values less than 10 to 2 digits try using the PUTN() function.

%do j=01 %to 12;
  %let j=%sysfunc(putn(&j,z2.));

Astounding — Thu, 20 Jun 2019 22:03:12 GMT

An easy way to get YYYYMM is to create a third macro variable:

%do y=2010 %to 2019;
   %do m = 1 %to 12;
      %let ym = %eval(&m + 100 * &y);
      %put The year and month:  &ym;
   %end;
%end;

Ksharp — Fri, 21 Jun 2019 11:13:54 GMT

data want;
set students_201001 - students_201910 ;
run;