This program will change the case for all of the character variables in a SAS data set. The key here is using the _CHARACTER_ keyword in the ARRAY statement. This will create an array of all the character variables in the dataset.
Once the array is created, you can apply any character functions on all of the character variables.
data cars; set sashelp.cars; array Chars[*] _character_; do i=1 to dim(Chars); Chars[i]=upcase(Chars[i]); end; drop i; run; title "Listing the First 10 Observations in the Cars dataset"; proc print data=cars(obs=10 keep=_character_) noobs; run;