Date:         Sun, 17 Aug 1997 14:36:24 -0700
Reply-To:     PDORFMA@ucs.att.com
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Paul Dorfman <PDORFMA@UCS.ATT.COM>
Organization: AT&T Universal Card Services
Subject:      Detecting CHAR/NUM in Data Step
Content-Type: text/plain; charset=us-ascii

Bruce Johnson, in particular, wrote:
 
>Is there a way to determine if a variable is character or numeric
>within a datastep?  For the purposes of this situation the use of proc
>contents output is prohibited.
 
Bruce:
 
Anthony Ayiomamitis is right: VARTYPE function has been added to
the list of DATA step functions in Base SAS. Personally, I prefer
to keep a macro like
 
%MACRO VARTYPE(DSNAME,VNAME);
   %STR(VARTYPE(OPEN("&DSNAME","I"),
        VARNUM (OPEN("&DSNAME","I"),"&VNAME")));
%MEND VARTYPE;
 
in an autocall library and to use it as a function-like statement
in a data step whenever needed. For instance, in the dataset
SASLIB.VRU the variable CALLDATE is numeric whilst the DUP_STMT is
character. Accordingly, the execution of the above yields:
 
134  DATA _NULL_;
135     CD_TYPE = %VTYPE(SASLIB.VRU,CALLDATE);
136     DS_TYPE = %VTYPE(SASLIB.VRU,DUP_STMT);
137     PUT CD_TYPE= DS_TYPE=;
138  RUN;
 
CD_TYPE=N DS_TYPE=C
NOTE: The DATA statement used 0.05 CPU seconds and 5564K.
 
Hope it's been helpful...
 
Paul M. Dorfman
AT&T UCS
Decision Support Systems
Jax, Fl