SAS: Non-sequential do loop within a data step - loops

Question

I would like to be able to execute a do loop for a non-sequential set of values. The way I have written this code runs a new data step for each value - so therefore the end product is a data table with a column added for the final value of the do loop only. What I want is for the the values in the varlst to loop through the if/then statements - thereby adding multiple columns to the table - without executing a new data step each time (which only results in adding one final column to the table).
INPUT DATA
DATA have;
INPUT id order Q3 Q5 Q6 Q50 Q75 Q102;
DATALINES;
1 1 2 0 7 2 2 0
1 2 3 0 5 5 3 0
3 1 6 1 7 2 7 1
3 2 6 0 7 5 7 0
6 1 3 1 4 7 7 2
6 2 5 2 7 7 7 1
7 1 3 5 6 5 3 0
7 2 4 1 7 5 2 1
9 1 4 1 6 5 6 1
9 2 1 3 5 7 5 0
;
run;
/********/
%macro test;
%let varlst=2 3 5 6 50 75 102 /*more values*/;
%do i=1 %to %sysfunc(countw(&varlst));
%let value=%scan(&varlst,&i);
data want;
set have;
by id order;
if Q&value ne lag(Q&value) and not first.id then do;
Q&value.Equal = 0;
end;
if Q&value=lag(Q&value) and not first.id then do;
Q&value.Equal = 1;
end;
%end;
run;
%mend;
%test;
/**********/
OUTPUT
id order Q3 Q5 Q6 Q50 Q75 Q102 Q102Equal
1 1 2 0 7 2 2 0 .
1 2 3 0 5 5 3 0 1
3 1 6 1 7 2 7 1 .
3 2 6 0 7 5 7 0 0
6 1 3 1 4 7 7 2 .
6 2 5 2 7 7 7 1 0
7 1 3 5 6 5 3 0 .
7 2 4 1 7 5 2 1 0
9 1 4 1 6 5 6 1 .
9 2 1 3 5 7 5 0 0

Answer 1

Why don't you try using PROC COMPARE?
data have ;
input id order Q3 Q5 Q6 Q50 Q75 Q102;
cards;
1 1 2 0 7 2 2 0 .
1 2 3 0 5 5 3 0 1
3 1 6 1 7 2 7 1 .
3 2 6 0 7 5 7 0 0
6 1 3 1 4 7 7 2 .
6 2 5 2 7 7 7 1 0
7 1 3 5 6 5 3 0 .
7 2 4 1 7 5 2 1 0
9 1 4 1 6 5 6 1 .
9 2 1 3 5 7 5 0 0
;;;;
proc compare
data=have(where=(order=1))
compare=have(where=(order=2))
outdiff out=want
;
id id ;
var q: ;
run;