how to use retain statement in SAS to populate missing data?

Question

I have a dataset which has multiple rows of data for a given person, but only the first row of the person's information contains their name. The rest of the rows of that person's data have the name field missing. I think I can use the retain statement to populate the name, but nothing I try works.

Here is an example of the dataset structure I am working with:

    data test;
    input id $ value ;
    datalines;
    Bob 100
    .   200
    .   300
    Jim 475
    .   250
    .   300
    ;
    run;

Answer 1

I think the problem is that technically id is not missing in those rows, it equals ., even though when reading datalines with input statement you get empty id. Try this:

data test;
  input id $ value;

  /*store not empty ID in different retained variable*/
  retain current_id;
  if not missing(id) then current_id=id;
  else id=current_id;

datalines;
Bob 100
.   200
.   300
Jim 475
.   250
.   300
;
run;