RE: diff btw Procedures and Routines

You can use of both but when you use one over the other depends upon what 
you're trying to do. Procedures, for example, can help make your code much 
easier to read and understand since you can see exactly what is being passed 
into and returned from a given routine. I tend to use subroutines mainly for 
high level control functions such as in the main code loop of my programs and 
if I need to get a large section of hard to read code (like writing a block of 
HTML in CGI programs) out of more complex logic to improve readability.

As an example of this, let's say that you want to get a price for a widget for 
customer 123, if you use a subroutine, you end up with code like this:

eval item='widget'
eval custid=123
exsr getprice
eval itemprice=price

If you instead have a getprice procedure, your code now becomes:

eval itemprice=getprice('widget',123)

This not only improves readability but it encapsulates the function of getting 
a price and since something like that tends to be used very often, it could be 
moved into a service program which can be shared with other programs. Also, 
procedure names can be much longer than subroutine names so you can make the 
program more self-documenting. Also note that you can return data structures as 
the result of a procedure which is great for doing things like getting 
information about things like customers and products which may have fairly 
involved look-up logic. Again, these types of routines tend to be used by many 
programs so once you've written a procedure to do this, it can go in a service 
program to be used by other programs.

Matt

-----Original Message-----
From: MURALI DHAR [mailto:nmuralidhar@rediffmail.com]
Sent: Thursday, August 15, 2002 10:40 AM
To: rpg400-l@midrange.com
Subject: diff btw Procedures and Routines



why do we use procedures only in modules in ILE programs?why nt
subroutines?whats the diff ...plz kindly answer me
Best regards
Murali
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