Date:         Wed, 10 Mar 2004 18:35:41 -0500
Reply-To:     "Chang Y. Chung" <chang_y_chung@HOTMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Chang Y. Chung" <chang_y_chung@HOTMAIL.COM>
Subject:      Re: Substring Puzzle
Comments: To: Richard DeVenezia <radevenz@IX.NETCOM.COM>

On Wed, 10 Mar 2004 18:01:29 -0500, Richard A. DeVenezia
<radevenz@IX.NETCOM.COM> wrote:

>>A compiler change yes.  But is it a bug fix or a clarified feature.  Why
is
>z still 12 length?

Hi,

I have a hypothesis. if c is not initialized but used in an expression,
then sas assumes a numeric variable and convert it to a string using
best12 format. This is kind of consistent with the following results, too.
This is not a definitive test of this hypothesis, but...

Cheers,
Chang

data _null_;

  z  = substr(c,1,1);
  zz = trimn(d);

  length_z  = vlength(z);
  length_zz = vlength(zz);

  put (_all_) (= +(-1) "***" /);

run;
/* on log
z=
c=.
zz=.
d=.
length_z=12
length_zz=12
*/