SET statement in DO loop

[briani]

I recently came across some SAS code that contained a SET statement inside a DO loop.  Can someone explain to me exactly how SAS is processing the data or any papers that might help.  I understand arrays and loops, i just have never seen the set statement inside a loop before.

Thanks in Advance.

DATA NEW (KEEP=NAME DATE1-DATE20);

ARRAY DATES {20} DATE1-DATE20;

OBSNO + 1;

DO I=1 TO 20 UNTIL (LAST.NAME);

SET OLD;

BY NAME;

IF FIRST.NAME THEN OBSNO=1;

DATES{I} = DATE;

END;

[Tom · Accepted solution]

SET is an executable statement. So if you code it in a loop then it just reads one observation for each time it is called.

You have what has been termed a DOW loop.  See this earlier posting that has a link to an article on DOW loops.

https://communities.sas.com/message/140387#140387