Re: array handling

[MacWheel99@xxxxxxx]

Rich

I do this in RPG/400 from time to time.
At the start of the program in the "E" specifications I define the Table or
Array.
It may be a TABLE that you want as opposed to an Array, even though an RPG
Table functions similarly to what other langugages call an Array.

The "E" specifications for a pair of tables let's say call them
TABHLD for the 2 position legacy hold code and
TABMHS for the 2 position hold code.

When you are in the RPG program you can start the E line then F4 to be
prompted to fill in the appropriate fields like is this alpha or numeric.

Within the "C" specifications, the command is LOKUP
Field 1 has the value you want to look up in the TABHLD "array"
Field 2 has TABHLD (which table are you looking up, in a program that could
have several.
Field 3 has TABMHS name - sounds a bit redundant, but it works.
You also have some indicator, like 90 in the = field
This means "Find me the element in TABMHS that corresponds to this value I am
looking up in the TABHLD" and indicator 90 goes *ON if there is a match.
If 90 is in fact on, I move TABMHS contents (the one element) to some other
work field, because what is in TABMHS is going to change every time I do
another LOKUP.

At the very end of the program is a line
**
(two asterisks) meaning start of next table or array defined by the program
then the data for the table or array.

I like to do it in vertical column of HLD then MHS data for program
readability but sometimes on small ones I do it on one line
like an array called PER

**
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

which corresponds to periods (months of year) so that when I output Per,MM
where MM is the current calendar month, the whole thing looks nice.

The coding is a little different if your table or array is going to be
populated as a result of reading some data into the program, or being the
results of calculations, but same kind of format ... LOKUP is used to look up
one HLD info so as to get at the corresponding entry in the MHS and when it
really is an RPG array as opposed to matching tables, you use NAME (of array)
comma ELEMENT (of array) to address individual elements.  You can use LOKUP
with an array in which if you are successful finding what you looking for,
the ELEMENT is populated with whatever the address is.

If you have a numeric array the XFOOT command can sum all elements into a
grand total.

Hope I have been helpful.

I wrote this reply then did not send it right away & saw some more posts.
There are many alternatives.

One problem I have with reading stuff into an array when program is executing
is I never know how big to make the array ... whatever I do, reality will
change & it won't be big enough, so I am not too keen on that kind of
architecture.

With embedded SQL in RPG we can access the file that has the two codes, even
if the file is not indexed (of course if you have a logical view over the
HLD, you can CHAIN or other RPG access to matching HLD to get the
corresponding MHS) ... at the time that we have one of the needed values,
access to get just the matching field value.  That makes sense to me if the
program execution is not going to need access to all the values.

Depending on how the data is flowing into a set of arrays in a program, there
may be value in SORTA = sorting array so the data is sequenced before using
it.

In this case each element of the input array might be composed of both
values, then after the sort, split it into the two working arrays.

>       I am having a problem with an array in RPG
>  (caused mainly by my ignorance where RPG is concerned
>  since I am a COBOL kind of guy!).  What I am trying to
>  do is to read a file and load an array that will have
>  2 elements - a legacy hold code (2 positions) and a
>  MHS hold code (2 positions).  I then want to do a
>  lookup on this array by MHS hold code and find the
>  corresponding legacy hold code (later in the program).
>
>       Could someone be kind enough to coach me through
>  this?  I will be forever greatful.
>
>  Rich

MacWheel99@aol.com (Alister Wm Macintyre) (Al Mac)
BPCS 405 CD Manager / Programmer @ Global Wire Technologies Incorporated
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