Extend the last values for more periods

[apolitical]

I have this table

ID   Period   Value

A    1            10

A    2            50

A    3             30

B    1             20

B    2             50

I want to make a table that extends for each ID to period 5, filling the previously non-existent values with the last existing value. Like this.

ID   Period   Value

A    1            10

A    2            50

A    3             30

A    4             30

A    5             30

B    1             20

B    2             50

B    3             50

B    4             50

B    5             50

In the existing table, the last period could be different. How do I program this? Thanks.

[Astounding · Accepted solution]

It should be straightforward as long as your data set is sorted:

data want;

set have;

by id period;

output;

if last.id and period < 5 then do period = period + 1 to 5;

   output;

end;

run;

[apolitical]

Astoundingly simple solution. Thanks!

[ChrisNZ]

This looks like homework, What have you tried?

[apolitical]

Unfortunately this is not homework and there is no buddy to copy from...

[ChrisNZ]

@Astounding's code is the answer.

You can even shorten it slightly.

if last.id then do period = period + 1 to 5;