Re: Sorting an array w/multiple fields

FYI

I have the program written & using Sorta the results are not what I would 
have expected.  It sorts them -2, -4, -7, 0, 1, 4, 6   OK not sure why 
that is, but it does sort to some degree.

So I decided to use QSort using the link Barbara supplied as a reference.. 
 That works perfectly!! 

Thanks to everyone for your help. 

Steve Jones



Barbara Morris <bmorris@xxxxxxxxxx> 
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
10/17/2005 08:03 PM
Please respond to
RPG programming on the AS400 / iSeries <rpg400-l@xxxxxxxxxxxx>


To
rpg400-l@xxxxxxxxxxxx
cc

Subject
Re: Sorting an array w/multiple fields






sjones@xxxxxxxxxxxxxx wrote:
> 
> I need to sort the array by field one, field two, field three so the
> sorted array would end up like:
> 
> AAAAA , 85- , XXXXX
> AAAAA , 7, DDDDD
> BBBBB,  3- , CCCCC
> BBBBB , 4 , CCCCC
> 
> I saw some previous posts on using QSort, but I don't see an example on
> how to sort by multiple fields using it.
> 

Here's an example of QSort sorting a data structure:
http://archive.midrange.com/rpg400-l/200411/msg00039.html The procedure
called "CompByFirst" does basically what you want; it compares a ds
first by one subfield and then when those are equal, it tests another
subfield.  For three subfields, you'd just add more code at the place
where it returns zero.

To get the results you want, you'd have something like this:

   // compare field one first
   if ds1.fieldone > ds2.fieldone;
      return 1;
   elseif if ds1.fieldone < ds2.fieldone;
      return -1;
   // field one is equal.  Compare field two next
   if ds1.fieldtwo > ds2.fieldtwo;
      return 1;
   elseif if ds1.fieldtwo < ds2.fieldtwo;
      return -1;
   // field one and field two are equal.  Compare field three next
   if ds1.fieldthree > ds2.fieldthree;
      return 1;
   elseif if ds1.fieldthree < ds2.fieldthree;
      return -1;
   // All three fields are equal, so the ds's compare equal
   else;
      return 0;
   endif;