Date:         Fri, 11 Jan 2008 17:01:18 -0500
Reply-To:     SUBSCRIBE SAS-L Dan <deniseyu001@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         SUBSCRIBE SAS-L Dan <deniseyu001@GMAIL.COM>
Subject:      Question on Do-Whitlock (DOW) loop.

Hi. SASLers:

Could anyone help on the topic:

The original correct code is:

Proc Sort data = SAShelp.Class
out = Class;
by Sex Name;
run;

proc print ; run;

DATA do_Whitlock_last;
do until(EndoFile);
do until(last.Sex);
set Class end = EndoFile;
 by Sex;
 end;
 output;
 put Sex= Name=;
 end;
 stop; run;

The output is

Obs    Name       Sex    Age    Height    Weight

 1     Mary        F      15     66.5       112
 2     William     M      15     66.5       112


I was trying to modify the code using WHILE instesd of UNTIL and my code is
below. It is in a dead loop. Could anyone out there point out where my
misunderstandings are? Thanks a lot.

DATA do_Whitlock_last_Modify;
do until (EndFile);
do while (not LastSex);
set Class end = EndoFile;
 by Sex;

 LastSex=last.sex ;
 EndFile=EndoFile ;

 end;
 output;
 put Sex= Name= LastSex= EndFile=;
 end;

 put 'Test is running'

 stop; run;