Date:         Wed, 20 Jun 2007 01:46:05 -0700
Reply-To:     barry.debenham@TALK21.COM
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         barry.debenham@TALK21.COM
Organization: http://groups.google.com
Subject:      Re: deleting a substring from a string
Comments: To: sas-l@uga.edu
In-Reply-To:  <200706200419.l5JIGrl9004037@mailgw.cc.uga.edu>
Content-Type: text/plain; charset="us-ascii"

On 20 Jun, 05:19, navne...@CAMDEN.USYD.EDU.AU (Navneet Dhand) wrote:
> Dear all,
>
> I have a string (&str) with many variables (say age sex breed etc.). I use
> the tranwrd function to create another sting (&newstr) by deleting all
> variables one by one as shown below. This usually works well but fails
> when &str has a variable whose name is similar to another variable. For
> example, when &str has both 'age' and 'age2' variables, tranwrd deletes
> age from both the variables.
>
> %let e =1;
>  %let var = %scan(&str, &e);
>  %do %while(&var NE);
>   %let newstr = %sysfunc(tranwrd(&str,&var,));
>                               *blank after comma deletes &var from &str
>   %if (&newstr ne ) %then %do;
>
>                    /*other code requiring both &var and &newstr*/
>
>                                   %end;
> %let e = %eval(&e + 1);
> %let var = %scan(&str, &e);
> %end;
>
> Is there a way by which I can delete only the whole word (using tranwrd or
> any other function? The variable names in the string &str are unique.
>
> Any other suggestions of performing the same task would be appreciated.
>
> Thanks in advance,
> Navneet


I've outlined a method to remove words within a string below.

/* Set up macro variable mvar1 */
%LET mvar1 = str1 str2 str3 str4 str4 str5;

/* define macro to show workings - you'd just remove the code
   from this macro and place it into yours. */
%MACRO a(remove=);
%LOCAL newstr;
%LET i = 1;
 /* These %upcase calls will not be needed if your strings are case
sensitive*/
%let remove=%upcase(&remove);
%let mvar1=%upcase(&mvar1);
 /* check every word in the &mvar1 variable */
%do %until(%SCAN(&mvar1,&i)=);
 /* If the scanned word is not the same as the variable to be deleted
    then pass it on to build the new string */
 %IF %SCAN(&mvar1,&i) NE &remove %THEN
   %LET newstr = &newstr %SCAN(&mvar1,&i);
 %LET i = %EVAL(&i + 1);
%end;
 /* Show the contents of &newstr in the log
*/
%PUT newstr=&newstr;
%MEND  a;

%a(remove=str4);

Running the macro above gives the following note in the log.

newstr=str1 str2 str3 str5

I hope this is helpful.

Regards,

Barry D.