topic Re: Use string comparison in IF/ELSE in SAS Procedures

Use string comparison in IF/ELSE

Laura1890 — Mon, 08 May 2023 11:06:47 GMT

Hello community,

I am desperately trying to set up an IF/ELSE where the if-condition is based on a string comparison. If the variable is not equal to PRODET (I also tried 'PRODET') I want the macro to be executed. This is what looked pretty reasonable to me, but we tried various options.

DATA _NULL_;
IF (&v_modul_akt. NE PRODET)
THEN CALL EXECUTE ('%set_module_view');
RUN;

Re: Use string comparison in IF/ELSE

SASJedi — Mon, 08 May 2023 11:53:23 GMT

Text without quotes around it is interpreted as code. So in your program, both the text resolved from &v_module_akt. an the word PRODET are both interpreted as variable names:

DATA _NULL_;
   IF (&v_modul_akt. NE PRODET)
   THEN CALL EXECUTE ('%set_module_view');
RUN;

Sinc nothing in the program assigns a value to those variables, they are both missing, so the values are equal. In your log you should see a NOTE indicating that the variables are uninitialized.
Try this instead:

DATA _NULL_;
   IF ("&v_modul_akt." NE "PRODET")
   THEN CALL EXECUTE ('%set_module_view');
RUN;

And may the SAS be with you!

Re: Use string comparison in IF/ELSE

yabwon — Mon, 08 May 2023 12:05:13 GMT

I would even go 1 step further and do:

DATA _NULL_; IF symget("v_modul_akt") NE "PRODET") THEN CALL EXECUTE ('%set_module_view'); RUN;

to ensure that "strange" value of v_modul_akt won't blow up my sas 🙂

Re: Use string comparison in IF/ELSE

Laura1890 — Mon, 08 May 2023 13:01:21 GMT

Thanks for the help!

Unfortunately, I still struggle:

%LET v_modul_akt = PRODET;
DATA _NULL_;
IF (symget("&v_modul_akt.") NE "PRODET")
THEN CALL EXECUTE ('%set_module_view');
RUN;

This snippet still calls the macro, even though the if-statement says "PRODET" NE "PRODET"

Re: Use string comparison in IF/ELSE

yabwon — Mon, 08 May 2023 13:08:03 GMT

Read the code I typed...

Re: Use string comparison in IF/ELSE

Laura1890 — Mon, 08 May 2023 13:46:40 GMT

Got it, didn't realize that & needs to be deleted.