find the minmum of two dates that is not misssing

[lillymaginta]

id       date_1           date_2              date_3
1    .                     02/02/2012     01/01/2001    
2     01/11/2009     2/10/2011     01/01/2004    
3     01/08/2013      .                      2/10/2012
4    11/10/2015     01/01/1998     26/12/2014

I am trying to the find the minimum of three dates but I have some missing information so I want to retain the minmum among the one that is avaiable:

output

1 01/01/2001

2 01/01/2004

3 02/10/2012

4 01/01/1998

[PeterClemmensen · Accepted solution]

The MIN function already handles this issue? So the following will do

data have;
informat date_1 date_2 date_3 ddmmyy10.;
input id date_1 date_2 date_3;
format date_1 date_2 date_3 ddmmyy10.;
datalines;
1 .          02/02/2012 01/01/2001
2 01/11/2009 2/10/2011  01/01/2004
3 01/08/2013 .          02/10/2012
4 11/10/2015 01/01/1998 26/12/2014
;

data want;
   set have;

   newvar = min(date_1,date_2,date_3);
   format newvar  ddmmyy10.;
run;

[RW9]

Just to add, functions like min() can also accept ranges of variables which can make typing much easier when you have lots of variables:

newvar=min(of date_:);

Assumes of course all variables have same prefix (or you setup and array of them before).

[lillymaginta]

Thank you!