Using Parameters
Understanding Parameters
Parameters are used to transfer data values between the calling environment and the
procedure (or subprogram). Parameters are also known as arguments. Parameters are declared in the subprogram header, after the name
and before the declaration section for local variables.
Parameters are subject to one of the three parameter-passing modes: IN, OUT, and IN OUT.
- An IN parameter passes a constant value from the calling environment to the procedure.
- An OUT parameter passes a value from the procedure to the calling environment.
- An IN OUT parameter passes a value from the calling environment to the procedure and a possibly different value from the procedure back to the calling environment using the same parameter.
