topic Do something only on the First and Last Observation in a Data step. in SAS Programming

Do something only on the First and Last Observation in a Data step.

Nyfaria — Wed, 13 Mar 2019 15:27:57 GMT

data test ;
input @01 Client     $10.
        @08 Accounts      $10.;
  format Client     $10.
         Accounts      $10.;
  datalines;
Garcia      123456
Gibson      250486
Knapp      123456
Mueller      867530
run;

data _null_;
set test;
if FirstObservation then
put "Start";
put Client || " " || Accounts;
else if LasterObservation then
put Client || " " || Accounts;
put "End"
else
put Client || " " || Accounts;
run;

Above is an Example of what I want, but I don't know exactly how I would do it. My wanted output is:

Start

Garcia 123456

Gibson 250486

Knapp 123456

Mueller 867530

End

Any idea how to code this for real?

Re: Do something only on the First and Last Observation in a Data step.

PeterClemmensen — Wed, 13 Mar 2019 15:31:04 GMT

Hi and welcome to the SAS Communities 🙂

This is a fairly easy task. Where do you want this output to go though? In a txt file or the log or?

Re: Do something only on the First and Last Observation in a Data step.

carrieforeman — Wed, 13 Mar 2019 15:33:32 GMT

For the first observation you could use _n_=1 and the last the end=e option on the set statement to flag the end of a data set to be read in. e.g.

data _null_;
  set test end=e;
  if _n_=1 then do;
    put "Start";
    put Client || " " || Accounts;
  end;
  if e then do;
    put Client || " " || Accounts;
    put "End";
  end;
run;

Re: Do something only on the First and Last Observation in a Data step.

Nyfaria — Wed, 13 Mar 2019 15:42:07 GMT

You are my Hero.

Re: Do something only on the First and Last Observation in a Data step.

carrieforeman — Wed, 13 Mar 2019 15:53:55 GMT

No problem, glad I could help 🙂