how to have multiple functions in parameters field of jmeter preprocessor

I have two methods and i want to access it in script, using args[] array

String uuid = args[0];
log.info("uuid: " + uuid);

String mpi = args[1];
log.info("mpi: " + mpi);

this is giving me array out of bound exception, so can i have it like this in parameters bar or can i have the functions in the script