topic Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz in SAS Certification

SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

trapinka — Sat, 13 Oct 2018 17:59:18 GMT

This is question 5 from Chapter 2 SAS Certification Prep Guide, edition 2018

5. With the system option VALIDVARNAME=ANY, which of the following variable names is valid?

a 4BirthDate
b $Cost
c _Items_
d Tax-Rate
e All of the above

My answer is e.

Answer from the book

Correct answer: c
Variable names follow the same rules as SAS data set names. They can be 1 to 32 characters long, must begin with a letter (A-Z, either uppercase or lowercase) or an underscore, and can continue with any combination of numbers, letters, or underscores.

It seems that in the explanation missed VALIDVARNAME option, which is set to ANY. That means that there are no SAS rules to apply for variables names. Can you clarify the correct answer?

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Tom — Sat, 13 Oct 2018 20:25:22 GMT

I would say that C is technically correct since the others would require the use of a name literal and not the value as shown.

Try this code.

data test;
  length 4BirthDate $Cost _Items_ Tax-Rate 8 ;
run;
data test;
  length '4BirthDate'n '$Cost'n _Items_ 'Tax-Rate'n 8 ;
run;
proc contents data=test;
run;

But that is one poorly worded question.

E could reasonable be seen as the correct answer since this is what PROC CONTENTS shows.

A better question would include at least one value using a name literal to make it clearer what the list represented. Or a value that is illegal even using VALIDVARNAME=ANY, such as one that is all blanks or includes a null byte ('00'x). Then which answer was correct would NOT depend on how the user interpreted the meaning of the list.

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Cynthia_sas — Sat, 13 Oct 2018 22:22:17 GMT

Hi:

This is addressed in the errata or content update for the 4th edition, as shown here:

https://support.sas.com/en/books/content-updates-base-prep-guide-4th-edition.html

Look for Appendix 1 update. page 528, question 5.

Cynthia

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Tom — Sun, 14 Oct 2018 16:14:39 GMT

@Cynthia_sas wrote:

Hi:

This is addressed in the errata or content update for the 4th edition, as shown here:

https://support.sas.com/en/books/content-updates-base-prep-guide-4th-edition.html

Look for Appendix 1 update. page 528, question 5.

Cynthia

That correction does NOT actually fix the problems with the question. It just changes the answer to one that assumes the list of names it like what you would see in PROC CONTENTS output instead of what you would use in SAS code. The question is left uncorrected.

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Cynthia_sas — Sun, 14 Oct 2018 18:51:46 GMT

Tom:
Thanks for the feedback. I'll ask the Certification editors to take a look at the specific question.
Cynthia

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

sabisw — Mon, 15 Oct 2018 13:58:57 GMT

@Tom, thank you for your feedback. We can look into updating this question for our next release.

However, the question is asking when you use VALIDVARNAME=ANY which of names are valid. Yes, you can do it with name literal, but you must also declare

options validvarname=any

for it to work. This may be dependent upon which SAS environment you are using. For Windowing Environment, the default is set to VALIDVARNAME=V7.

If you do not set VALIDVARNAME=ANY in the OPTIONS statement then the following:

data test;
	length 4BirthDate $Cost _Items_ Tax-Rate 8;
run;
proc contents data=test;
run;

results in an error in the log that, 4BirthDate is not a valid SAS name.

However, in order for it to work you must declare options VALIDVARNAME=ANY and use name literal like below:

options validvarname=any;
data test01;
   length '4BirthDate'n '$Cost'n '_Items_'n 'Tax-Rate'n 8;
run;
proc contents data=test01;
run;

I tried the same thing in SAS Studio and without the

options validvarname=any

and it gave me the same error and then I did it with the options statement and declaring a name literal, and then I got the correct answer.

Base SAS is shipped with the system options being set to VALIDVARNAME=V7 and SAS Viya is shipped with the system options being set to VALIDVARNAME=ANY.

Here is a link to the documentation for more information: VALIDVARNAME=ANY System Option

I hope this helps and clarifies a bit more.

-Samantha

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Tom — Mon, 15 Oct 2018 14:29:35 GMT

Thanks @sabisw for your reply. And for proving my point.

The issue with the question is not really whether the names are valid, but whether the question is clear.

The names as listed in the question might be valid names, but they are not valid names for use in actual SAS code.

So whether C or E is the right answer depends on how the user interprets the question.

Therefore the question needs to be fixed to eliminate that ambiguity.

2    options validvarname=any;
3    data test;
4    	length 4BirthDate $Cost _Items_ Tax-Rate 8;
             -
             22
ERROR 22-322: Syntax error, expecting one of the following: a name, _ALL_, _CHARACTER_, _CHAR_,
              _NUMERIC_.

4  ! 	length 4BirthDate $Cost _Items_ Tax-Rate 8;
                           ----
                           22
ERROR: Alphabetic prefixes for enumerated variables (Tax-Rate) are different.
ERROR 22-322: Expecting a numeric constant.

5    run;

NOTE: The SAS System stopped processing this step because of errors.
WARNING: The data set WORK.TEST may be incomplete.  When this step was stopped there were 0
         observations and 3 variables.

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

sabisw — Mon, 15 Oct 2018 14:24:41 GMT

@Tom, Correct they are not valid SAS names therefore you have to use VALIDVARNAME=ANY and declare them as a name literal. That's the reason why without the VALIDVARNAME=ANY it doesn't work.

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Tom — Mon, 15 Oct 2018 14:31:12 GMT

@sabisw wrote:

@Tom, Correct they are not valid SAS names therefore you have to use VALIDVARNAME=ANY and declare them as a name literal. That's the reason why without the VALIDVARNAME=ANY it doesn't work.

Great, so you will have someone re-word the question to remove the ambiguity?

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Cynthia_sas — Mon, 15 Oct 2018 14:31:36 GMT

Hi:
Well, I would have liked it if the option had been named:
VALIDVARNAME_WHEN_USED_AS_NAME_LITERAL
or made it:
VALIDVARNAME=ANY_AS_NAME_LITERAL -- but they didn't ask me for input into the option name.
Sigh.
Cynthia

Re: SAS Prep Guide SAS 9 4th edition question on Ch 2 quiz

Tom — Mon, 15 Oct 2018 14:36:55 GMT

The fact that name literals are required is part of what makes the question poor. It basically is penalizing test takers that understand SAS too well.