Peculiar Behavior of DO in a SELECT Block

[Kurt_Bremser]

I just came across code that looks like this:

data test;
input x1;
select (x1);
  when (1) do
    x2 = 1;
    x3 = 1;
  end;
  otherwise;
end;
datalines;
1
0
;

and I immediately thought "ERROR because of missing semicolon!", but this code works, and it even works as obviously intended.

Does anybody know why SAS does not complain here?

[FreelanceReinh · Accepted solution]

Yes, it's the iterative DO statement (with x2 as the index variable), just written in a "peculiar" way, not a DO-END block.

[Kurt_Bremser]

Oh yes, that's it! It works, but it nicely fits a schlockmercenary quote I posted yesterday:

"When it's stupid and it works, it's still stupid, and you're lucky"