Looping around a whole data step in SAS - sas

Question

So I have a following code:
%let macroVar = Var1 Var2;
Data new1;
Set old1 (keep= count &macroVar.);
Run;
Proc means data = new1 nway missing noprint;
Class var1;
Var count;
Output out= out_var1 sum=;
Proc means data = new1 nway missing noprint;
Class var2;
Var count;
Output out= out_var2 sum=;
How can I write out the two proc means in one data step, using the macro variable I set up at the beginning?
Many thanks

Answer 1

Why not just do it in one PROC MEANS call?
%let varlist=sex age ;
proc means data=sashelp.class missing noprint;
class &varlist;
ways 1;
var height;
output out=want sum=;
run;
Result:
Obs Sex Age _TYPE_ _FREQ_ Height
1 11 1 2 108.8
2 12 1 5 297.2
3 13 1 3 184.3
4 14 1 4 259.6
5 15 1 4 262.5
6 16 1 1 72.0
7 F . 2 9 545.3
8 M . 2 10 639.1
If you really must have separate output datasets then it will be faster to generate them from the output above.
%macro sum_counts(varlist,data=,var=count);
%local i n;
%let n=%sysfunc(countw(&varlist));
proc means data=&data missing noprint ;
class &varlist;
ways 1;
var &var;
output out=_summary_ sum=;
run;
%do i=1 %to &n;
data new&i;
set _summary_;
where _type_=2**(&n-&i);
keep %scan(&varlist,&i) &var;
run;
%end;
%mend sum_counts;
Example:
263 options mprint;
264 %sum_counts(varlist=sex age,data=sashelp.class,var=height);
MPRINT(SUM_COUNTS): proc means data=sashelp.class missing noprint ;
MPRINT(SUM_COUNTS): class sex age;
MPRINT(SUM_COUNTS): ways 1;
MPRINT(SUM_COUNTS): var height;
MPRINT(SUM_COUNTS): output out=_summary_ sum=;
MPRINT(SUM_COUNTS): run;
NOTE: There were 19 observations read from the data set SASHELP.CLASS.
NOTE: The data set WORK._SUMMARY_ has 8 observations and 5 variables.
MPRINT(SUM_COUNTS): data new1;
MPRINT(SUM_COUNTS): set _summary_;
MPRINT(SUM_COUNTS): where _type_=2**(2-1);
MPRINT(SUM_COUNTS): keep sex height;
MPRINT(SUM_COUNTS): run;
NOTE: There were 2 observations read from the data set WORK._SUMMARY_.
WHERE _type_=2;
NOTE: The data set WORK.NEW1 has 2 observations and 2 variables.
MPRINT(SUM_COUNTS): data new2;
MPRINT(SUM_COUNTS): set _summary_;
MPRINT(SUM_COUNTS): where _type_=2**(2-2);
MPRINT(SUM_COUNTS): keep age height;
MPRINT(SUM_COUNTS): run;
NOTE: There were 6 observations read from the data set WORK._SUMMARY_.
WHERE _type_=1;
NOTE: The data set WORK.NEW2 has 6 observations and 2 variables.