topic Re: How to mask & in datastep in SAS Programming

How to mask & in datastep

gyambqt — Thu, 14 Oct 2021 00:02:25 GMT

Hi Experts,

Given the program below how do I prevent the warnings?

data test;
call symputx('test','&test2');
test=resolve('&test');
run;

Thanks

Re: How to mask & in datastep

ballardw — Thu, 14 Oct 2021 00:16:03 GMT

Which warning?

Macro variables do not resolve inside single quotes. If you have a macro variable named test2 and want the value treated as text you would use "&test2"

You may have to share exactly what you expect as it isn't obvious from either your question or code.

Re: How to mask & in datastep

Patrick — Thu, 14 Oct 2021 00:20:28 GMT

Macro variable &test2 would need to exist when using resolve(). If you just want to retrieve the value from &test then use symget() instead.

%let test2=some value;
data test;
  call symputx('test','&test2');
  test=resolve('&test');
  test2=symget("test");
run;

Re: How to mask & in datastep

Quentin — Thu, 14 Oct 2021 00:33:36 GMT

Hi,

Is your goal to make a macro variable TEST which has the value &test2, and then use the RESOLVE function to write that value to a data step variable TEST without treating the & in the value as a macro trigger?

If so, then %superq can help:

1    data test;
2    call symputx('test','&test2');
3    test=resolve('%superq(test)');
4    put test= ;
5    run;

test=&test2
NOTE: The data set WORK.TEST has 1 observations and 1 variables.

but unless this is an academic exercise, it might be worth describing more of the big picture behind your goal.

Re: How to mask & in datastep

gyambqt — Thu, 14 Oct 2021 02:05:04 GMT

Can you pls explain why is it working? I understand both %superq and resolve but what is happening when they used together?

Re: How to mask & in datastep

Quentin — Thu, 14 Oct 2021 13:43:23 GMT

Without %superq, the resolve function resolves the macro variable reference &test, to the value &test2 and it sees that as a macro variable reference so tries to resolve the macro variable TEST2, which doesn't exist, so it throws the warning.

With %superq the resolve function resolves the macro variable reference &test, to the value [masked &]test2 which is not a macro variable reference so there is no attempt to resolve TEST2. The job of %SUPERQ is to resolve a macro variable, and then mask any & or % in the resolved value.

To be honest, I wasn't sure %SUPERQ would work here, because I don't use the RESOLVE function much. But it looks to me like it is doing its usual job.

Re: How to mask & in datastep

gyambqt — Thu, 14 Oct 2021 14:29:34 GMT

thanks