Compare columns and make one column

[Astounding]

OK, looks like you didn't heed my warning.  You accepted a solution as correct when it can give the wrong answer:

• Whenever class5 is missing
• Whenever two incoming variables are missing (not including the combination of class1 and class2 being missing)

Maybe these situations won't occur in your data, but check them!

[Shmuel]

@Astounding you are absolutely right.

The code should be:

data want;

   set have;

        array clx class1-class5 ;  

        class = ' ';

        do i=1 to dim(clx);

           if  class = ' ' and clx(i) ne ' ' then class = clx(i);

           else if clx(i) < class and

                       clx(i)  ne ' ' 

                  then class = clx(i);

       end;

      keep id class;

run;