RE: RPG Error or ?

Henrik,

We have mental models of how things work (logical to us). In this case it appears your mental model is that '' will be padded with low values. Other mental models have the longest string getting truncated and compared against the smaller string (doesn't C work this way?). Both models don't match what is occurring in RPG - blank padding on the shortest string to compare against the longest string. That's the source of your confusion.

Paul Morgan

Principal Programmer Analyst
IT Supply Chain/Replenishment

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Henrik Rützou
Sent: Tuesday, October 11, 2011 10:52 AM
To: RPG programming on the IBM i / System i
Subject: Re: RPG Error or ?

To me it isn't logical,

if you reset a variable field to "no value" you do it with

string = '';

%len(string) will display 0

so why is a compare with '' not equal to the setting of the field while
it (whatever there may be in memory) works if you do

string = 'abc';
if string = 'abc'; // will pass

string = 'abcd';
if string = 'abc'; // will fail

?

I have of course just changed my code to %len(string) > 0;





On Tue, Oct 11, 2011 at 4:40 PM, <rob@xxxxxxxxx> wrote:

If I change it to:
string = x'0515' + 'abc';
string='';
and debug it on an active line after the above I get
00000515 81828300 - ....abc

but if I change it to:
/free
*inlr=*on;
string='';
then none of the DSPLY's kick in, and

EVAL string :x

00000000 00000000 00000000 00000000 - ................
so, apparently
00050515 81828300 00000000 00000000 - ....abc........
is less than
00000000 00000000 00000000 00000000 - ................

Rob Berendt
--
Group Dekko
Dept 1600
Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
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Kendallville, IN 46755
http://www.dekko.com





From: Henrik Rützou <hr@xxxxxxxxxxxx>
To: "RPG programming on the IBM i / System i" <rpg400-l@xxxxxxxxxxxx>
Date: 10/11/2011 10:00 AM
Subject: RPG Error or ?
Sent by: rpg400-l-bounces@xxxxxxxxxxxx



Is it me that has misunderstood something or what would you expect
displayed from this code:

d string s 52a varying

string = x'0515' + 'abc';
or
string = x'4015' + 'abc';

// dosn't work (but works if x'4040' + 'abc')
if string > '';
dsply 'hello 1';
endif;

// works
if string <> '';
dsply 'hello 1';
endif;

// works
if %len(string) > 0;
dsply 'hello 2';
endif;


--
Regards,
Henrik Rützou

http://powerEXT.com <http://powerext.com/>
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