Re: Passing pointers as parms

[Jim Langston <jimlangston@xxxxxxxxxxxxxxxx>]

Please correct me if I am wrong.

When you omit the Value keyword, you are passing a pointer.  This pointer
should point to the beginning of the memory you are passing, whether it is
a string, a number, a data structure, etc..

So, in this case you are passing a pointer to memory that contains a data
structure (as you say, a pointer to a data structure).

I am not sure of all the peculiarities of OS/400, but mainly on PCs, but
I'm guessing it's exactly the same.  The compiler builds the call to pull
from the stack (parameter list) the pointer and to know what to do with it.

If you pass a pointer to the data structure yourself, then have a data 
structure pointer point to this value, you are doing manually the same thing
that RPG and the OS are already doing.  There should be no reason to do this
I could think of, unless you are looking for some side affect of this.

If you are concerned about the size of the data being passed don't be, you
are only passing a pointer regardless which is (most likely) 4 bytes or
maybe even 8 bytes (are RISC boxes 64 bit?).

Regards,

Jim Langston

Contractor1@Parkdalemills.com wrote:
> 
> When you omit the VALUE keyword when passing a parameter, are you passing a
> pointer to a pointer? And in this case a pointer to a pointer to a data
> structure?
> 
> Patrick Conner
> www.ConnecTown.com
> (828) 244-0822
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