topic Re: SAS default length in SAS Programming

SAS default length

Davidliu494 — Wed, 17 Oct 2012 20:14:26 GMT

Here's a SAS BASE certification exam sample question:

The following SAS program is submitted:

data work.flights;

destination = 'CPH';

select(destination);

when('LHR') city = 'London';

when('CPH') city ='Copenhagen';

otherwise;

end;

run;

Which of the following is the value of the CITY variable?

A. London

B. Copenh

C. Copenhagen

D. ' ' (missing char value)

why is the answer B not C? also, within the Select statement, what is the function of 'otherwise'?

Thank you!

Re: SAS default length

Davidliu494 — Wed, 17 Oct 2012 20:26:16 GMT

nvm... it's because variable CITY took the length of the first instance of the variable, which is 'London'

Re: SAS default length

Linlin — Wed, 17 Oct 2012 20:32:37 GMT

The length of new variable "city" was set by "London". using "otherwise" because destination may have values other than "LHR" and "CPH".

try adding a length statement:

data work.flights;

length city $ 10;

destination = 'CPH';

select(destination);

when('LHR') city = 'London';

when('CPH') city ='Copenhagen';

otherwise;

end;

run;

Re: SAS default length

Tom — Wed, 17 Oct 2012 20:35:01 GMT

Otherwise is where it branches when none of the other conditions are met. In this case it does nothing. You can cause run-time errors if you forget to include the otherwise category and your actual data fails to match one of the other conditions. Example:

ERROR: Unsatisfied WHEN clause and no OTHERWISE clause at line 110 column 3.