Sorting items in an array

[Jason]

Hello COBOL experts,

I have a question i'm sure someone can help me with.

I have an array:

01 ARRAY.
05 ARRAY-ITEMS pic x(256) occurs 10 times.

How do I go about sorting this array so the items are all in alphabetical order?

Any advice greatly appreciated!

[Vincent (Bryan) Coen]

Read up on the SORT verb.

On 23/05/2022 17:49, flaneur7508 wrote:

Hello COBOL experts,

I have a question i'm sure someone can help me with.

I have an array:

01 ARRAY.
05 ARRAY-ITEMS pic x(256) occurs 10 times.**

How do I go about sorting this array so the items are all in
alphabetical order?

Any advice greatly appreciated!

[serge lacombe]

   IDENTIFICATION DIVISION.
   PROGRAM-ID. prg.
   DATA DIVISION.
   WORKING-STORAGE SECTION.
  *
   01  array.
       03  array-items occurs 10 pic x(256).
   01  ind pic 99.
  *
   PROCEDURE DIVISION.

  *
   debut.
      move "zzz" to array-items (1)
      move "aaa" to array-items (2).
      move "bbb" to array-items (3).
      move "yyy" to array-items (5).
      move "ddd" to array-items (6).
      move "ppp" to array-items (7).
      move "mmm" to array-items (8).
      move "ggg" to array-items (9).
      move "iii" to array-items (10).
      sort array-items ascending key  array-items.
      perform varying ind from 1 by 1 until ind > 10
          display array-items (ind) (1 : 3)
      end-perform.
      stop run.

[Jason]

That’s very useful, I thought SORT only works on file sorts.

Although my program compiles I have a problem.

01 KEY-GROUP-SAVED-ARRAY.
02 KEY-GROUP-SAVED PIC X(256) OCCURS 100 TIMES.
01 GROUP-INDEX PIC 9(3) VALUE ZERO.

The values in KEY-GROUP-SAVED are

KEY-GROUP-SAVED(1) = one
KEY-GROUP-SAVED(2) = two
KEY-GROUP-SAVED(3) = three
KEY-GROUP-SAVED(4) = four
KEY-GROUP-SAVED(5) = five
KEY-GROUP-SAVED(6 to 100) = SPACES

…….

DISPLAY KEY-GROUP-SAVED-ARRAY LINE 1 POSITION 1.
SORT KEY-GROUP-SAVED ON ASCENDING KEY KEY-GROUP-SAVED.
DISPLAY KEY-GROUP-SAVED-ARRAY LINE 31 POSITION 1.
ACCEPT INPUT-KEY.

When I run this, the array is display as expected (i.e. one, two, three…) prior to the SORT

After the sort, when I display the array I just get spaces. I.e. the SORT is removing the content of the array.

I double checked in the GNUcobol docs, and the syntax appears to be correct.

What have I broken?

edit. So of course the first 95 elements are indeed spaces post SORT. That's my mistake! Thank you Serge & Vincent!!

[Simon Sobisch]

As you found out - spaces sorts less than the rest by default. To work on this you could do one of the following:

• initialize the table keys via VALUE HIGH-VALUE
• define a sort collation which only includes 'A' through 'Z', 'a' through 'z', '0' through '9' and use this - everything left out will be sorted as equally to high-value
• if you know the amount of entries: add DEPENDING ON to the OCCURS - this will also speed up the SORT

[Vincent (Bryan) Coen]

The trick here is to initialise the table as high-values before loading.

You should also have a vars set to the max table size AND test against
that value every time you increase the count, i.e.,

add 1 to group-index
if group-index > key-group-table-size
     do a error-procedure such as display a warning message etc.

Now sort the table ascending. ( low to high)

Then process the table with a check i.e.,
perform forever
              if key-group-saved (group-index) = high-value
                   or group-index > key-group-table-size
                                   exit perform  *> search ends
              end-if
              do processing for table
                   with a exit perform cycle
end-perform

Simple

Vince

On 24/05/2022 07:27, flaneur7508 wrote:

That’s very useful, I thought SORT only works on file sorts.

Although my program compiles I have a problem.

01 KEY-GROUP-SAVED-ARRAY.
02 KEY-GROUP-SAVED PIC X(256) OCCURS 100 TIMES.
01 GROUP-INDEX PIC 9(3) VALUE ZERO.

The values in KEY-GROUP-SAVED are

KEY-GROUP-SAVED(1) = one
KEY-GROUP-SAVED(2) = two
KEY-GROUP-SAVED(3) = three
KEY-GROUP-SAVED(4) = four
KEY-GROUP-SAVED(5) = five
KEY-GROUP-SAVED(6 to 100) = SPACES

…….

DISPLAY KEY-GROUP-SAVED-ARRAY LINE 1 POSITION 1.
SORT KEY-GROUP-SAVED ON ASCENDING KEY KEY-GROUP-SAVED.
DISPLAY KEY-GROUP-SAVED-ARRAY LINE 31 POSITION 1.
ACCEPT INPUT-KEY.

When I run this, the array is display as expected (i.e. one, two,
three…) prior to the SORT

After the sort, when I display the array I just get spaces. I.e. the
SORT is removing the content of the array.

I double checked in the GNUcobol docs, and the syntax appears to be
correct.

What have I broken?