Compare two columns first alphabetically?

[Mattress58]

How can I compare two columns to get which one is first alphabetically? I want to put which is first in a 3rd column.

Example:

Column1 = Kelly

Column2 = Katie

Column3 would be Katie because it is first alphabetically.

dataset = Rentals

[ballardw · Accepted solution]

Case of letters is an issue as in this example:

data work.example;
   informat column1 column2 $10.;
   input column1 column2;
   if column1 < column2 then column3 = column1;
   else column3 = column2;
datalines;
Kelly Katie
kelly Katie
Kelly katie
kelly katie
;
run;

If case should not be considered then you can use either UPCASE(column1) and UPCASE(column2) or LOWCASE in the comparison.

[hbi]

Borrowing from ballardw's example, you can also use "><" (min) and "<>" (max). It works differently than the min() and max() functions, which only support numeric variables. 

data work.example;
   informat column1 column2 $10.;
   input column1 column2;
   min_of_col1_col2 = (column1 >< column2);
   max_of_col1_col2 = (column1 <> column2);
datalines;
Kelly Katie
kelly Katie
Kelly katie
kelly katie
;
run;