topic Re: Unquoting in SAS in SAS Programming

Unquoting in SAS

kaushal2040 — Wed, 19 Aug 2015 15:22:33 GMT

Hello Forum,

Use of %unquote is not necessary even though it is quoted with %str in code below (Automatic unquoting). I wonder under which conditions %unquote is explicitly required to get the resolved value back.

Thanks !!!

options symbolgen;

%let macvar=%str(proc print;run;);

%put &macvar;

SYMBOLGEN: Macro variable MACVAR resolves to proc print;run;

SYMBOLGEN: Some characters in the above value which were subject to macro

quoting have been unquoted for printing.

proc print;run;

Re: Unquoting in SAS

ballardw — Wed, 19 Aug 2015 15:28:47 GMT

Basically needed when you had to %quote (or other functions) because the string you are manipulating has special characters such as % or & that are not macro function or variables (at least at that point in the program) that you do not want resolved.

From the documentation see the difference in these two data steps:

%let val = aaa;

%let testval = %str(%'&val%');

data _null_;

val = &testval;

put 'VAL =' val;

run;

and

data _null_;

val = %unquote(&testval);

put 'VAL =' val;

run;

I try to avoid macro quoting as much as practical as it often means I've complicated issues somewhere along the line.

Re: Unquoting in SAS

kaushal2040 — Wed, 19 Aug 2015 16:57:19 GMT

Thanks, ballardw.

This example explains a lot. I understand when there are macro triggers masked in macro variable then %unquote is required to get resolved value.