topic Re: Mask a variable in SAS Data Management

Mask a variable

Citrine10 — Tue, 28 Jun 2022 12:00:52 GMT

Hi there

I am trying to use %nrstr and %str. I am passing my variable in the function however it wont work when trying to reference the value of the variable

e.g.

%let myvar = crazy&609

%let maskedname = %nrstr(&myvar.);
%put &maskedfile.;

the masking works fine when doing this but not when using the variable:

%let maskedname = %nrstr(crazy&609);

Re: Mask a variable

PaigeMiller — Tue, 28 Jun 2022 12:05:31 GMT

To use &MYVAR, you need to quote the variable

%let myvar=crazy&609;
%put The value of MYVAR is %bquote(&myvar);

%STR and %NRSTR should be used when you can see the special character in the text inside %STR() or %NRSTR(). In this case, when you use &myvar, you can't see the special character, you see a macro variable &myvar which may or may not contain special characters, so the quoting functions are needed here.

Re: Mask a variable

Citrine10 — Tue, 28 Jun 2022 12:11:09 GMT

Hi Paige, thank you

I would need to use NRSTR as i have special characters in the name of the variable. What other alternatives are there?

Re: Mask a variable

PaigeMiller — Tue, 28 Jun 2022 12:34:52 GMT

@Citrine10 wrote:

Hi Paige, thank you

I would need to use NRSTR as i have special characters in the name of the variable. What other alternatives are there?

Provide an example.

Re: Mask a variable

Citrine10 — Tue, 28 Jun 2022 12:37:11 GMT

%let myvar=crazy&609; %put The value of MYVAR is %nrstr(&myvar);

%let myvar=craz!609; %put The value of MYVAR is %nrstr(&myvar);

Re: Mask a variable

PaigeMiller — Tue, 28 Jun 2022 12:49:24 GMT

For this example, no quoting or %STR/%NRSTR is needed, but it will work with quoting

%let myvar=craz!609;
%put The value of MYVAR is %bquote(&myvar);
%put The value of MYVAR is &myvar;

Re: Mask a variable

Citrine10 — Tue, 28 Jun 2022 12:59:36 GMT

ok but how will it work with some special characters and mnemonics as %NRSTR masks & and %.

Re: Mask a variable

Quentin — Tue, 28 Jun 2022 13:29:30 GMT

You still need to give an example with mnemonics you are trying to mask. If you're trying to mask & or % which result from resolving a macro variable and might be seen as a macro trigger, then you can use %superq, e.g.:

%let myvar=craz&foo;   *will throw warning foo not resolved ;
%put The value of MYVAR is %superq(myvar); *no warning because & is masked ;

Note that masking of & or % is only needed when they would be seen as macro trigger. The macro processor knows that a macro name and macro variable name must start with a letter, so &609 or %609 cannot be seen as macro triggers.

%let myvar=craz&609; 
%put The value of MYVAR is &myvar;

%let myvar=craz%609; 
%put The value of MYVAR is &myvar;

Depending on how you use the macro variable, it's possible that in &609 the & might be seen as an AND operator.

Macro quoting is a hard subject. It's an almost impossible subject to try to learn without an example.

Re: Mask a variable

PaigeMiller — Tue, 28 Jun 2022 13:32:45 GMT

@Citrine10 wrote:
ok but how will it work with some special characters and mnemonics as %NRSTR masks & and %.

Provide examples.