Re: Reasons for %Lookup failure

[Rich Duzenbury <rduz-midrange@xxxxxxxxxxxxxxxxxxx>]

On Wed, 2004-06-30 at 18:42, CarollaT@xxxxxxxxxxxxxx wrote:
> I am having a problem with the %Lookup BIF.  I am performing a %Lookup on an
> array that has the value in it (I have debugged), and yet the %Lookup does
> not produce the index number of the array element.  
> 
> The array is very simple:
> D SiteCursor      S              3A   Inz(*Blanks)
> D                                     Dim(300)    
> D                                     Ascend 

Try it without ascend.  

>From the RPG Reference:

"Ascending sequence means that the array or table entries must start
with the lowest data entry (according to the collating sequence) and go
to the highest. Items with equal value are allowed."

I suspect that when you tell RPG that the data is already sorted, it
believes you.  The search algorithm probably uses some kind of binary
search when you call for the ASCEND keyword, versus an exhaustive search
when you don't.

--
Regards,
Rich

Current Conditions in Des Moines, IA
Broken Clouds
Temp 73.4F
Winds out of the Southeast at 6mph