RPG Clear Operation

The RPG CLEAR operation is a handy way to initialize all the elements in a structure or variable. It sets numeric fields to zero, character fields to blanks and indicator fields to '0'. By specifying *NOKEY in factor 1, you can clear all fields in a DISK record format except key fields.

However, there is a catch. When the CLEAR operation is applied to a record format name, only output fields are affected. For file record formats with WORKSTN specified as the device in the file specification, only fields with a usage of output or both are affected by the CLEAR. Fields in DISK, SEQ or PRINTER file record formats are cleared only if those record formats are output in the program. Input-only fields are not affected.

This means that if you define a file for input-only in the file specification record, any attempt to CLEAR its record format will have no effect at all.