Date:         Tue, 2 Jun 1998 20:31:25 +1000
Reply-To:     Tim Churches <tchurch@IBM.NET>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Tim Churches <tchurch@IBM.NET>
Subject:      SAS Trap: ordering of FORMAT= in ATTRIB statement
Content-Type: text/plain; charset=us-ascii

This was a new one on me: the order in which FORMAT= is used an ATTRIB
statement affects the length of character variable. Easier to illustrate
than explain:
 
************************* ;
proc format ;
 value $bug
  '0000' = 'This must be a bug'
  other = 'Or maybe a feature' ;
 run ;
 
data test1 ;
 attrib testvar length=$4 format=$bug.  ;
 testvar = '0000' ;
 run ;
 
data test2 ;
 attrib testvar format=$bug. length=$4 ;
 testvar = '0000' ;
 run ;
 
proc contents data=test1 ;
 run ;
 
proc contents data=test2 ;
 run ;
************************* ;
 
You would expect the variable testvar to have a length of 4 in both
test1 and test2 datasets, no? Wrong! Testvar is assigned a length of 4
in the first dataset, but a length of 18 in the second dataset, even
though the only difference between the two data steps which create the
datasets is the position of the FORMAT= in the ATTRIB statement. I have
tried this under 6.08 for VAX/VMS, 6.11 for Unix and 6.12 TS045 for
Windows, all with the same results. I can't find any mention in the
manuals that the order of FORMAT= and LENGTH= in an ATTRIB statement is
important, but clearly it is.
 
Tim Churches