topic Re: drop/keep vs drop=/keep= in SAS Programming

drop/keep vs drop=/keep=

clqa — Thu, 20 Sep 2018 20:50:07 GMT

is there any difference in the drop, keep, (drop=), and (keep=) function?

Re: drop/keep vs drop=/keep=

Cynthia_sas — Thu, 20 Sep 2018 21:04:21 GMT

Hi:
We cover the use of DROP and KEEP statements versus DROP= and KEEP= options in our Programming 1 and Programming 2 classes. For a discussion of the differences, you might want to look in the documentation.

Cynthia

Re: drop/keep vs drop=/keep=

Reeza — Thu, 20 Sep 2018 21:08:39 GMT

Yes.
DROP/KEEP are STATEMENTS usually only valid in a SAS data step.

DROP=/KEEP= are data set OPTIONS. They can be used almost anywhere you reference a SAS data set including in a SQL step.

They act at different points of time, for example a KEEP statement in the data step will only keep variables but they're available for calculations. If you use DROP = on a data set that's being read for example that data is not read into the step and cannot be used in calculations.

data want1 (drop=weight) want2 (drop=height); *variables are dropped for output data sets;

set sashelp.class (drop=age); *age is dropped before the data is read in;

new_name = catt(name, ' Smith');

drop name;*name is dropped for all data sets but is available for calculations;

run;