>>SOURCE FORMAT IS FREE
*> cobol-redefines-example.cob — one memory area, two views
*> Dialect: GnuCOBOL 3.x, free format
*> Status : desk-checked against the GnuCOBOL 3.2 Programmer's Guide;
*>          NOT compiled (no cobc on the authoring machine)
*> Inputs : none
*> Outputs: DISPLAY lines on the console
*> Build  : cobc -x cobol-redefines-example.cob
*> Run    : ./cobol-redefines-example   (Windows: cobol-redefines-example.exe)
IDENTIFICATION DIVISION.
PROGRAM-ID. REDEFINES-DEMO.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
*> View 1: eight characters of text.  View 2: three numbers in the
*> very same eight bytes.  Only the subject (Order-Date) has a VALUE.
01 Order-Date               PIC X(8) VALUE "20260905".
01 Order-Date-Parts REDEFINES Order-Date.
   05 OD-Year               PIC 9(4).
   05 OD-Month              PIC 9(2).
   05 OD-Day                PIC 9(2).
*> A record whose tail means different things depending on a type
*> code.  Both variants redefine TR-Body and are exactly 24 bytes.
01 Transaction-Record.
   05 TR-Type               PIC X.
      88 TR-Is-Payment      VALUE "P".
      88 TR-Is-Refund       VALUE "R".
   05 TR-Body               PIC X(24).
   05 TR-Payment REDEFINES TR-Body.
      10 PAY-Account        PIC 9(8).
      10 PAY-Amount         PIC 9(7)V99.
      10 PAY-Method         PIC X(3).
      10 FILLER             PIC X(4).
   05 TR-Refund REDEFINES TR-Body.
      10 REF-Original-Ref   PIC X(12).
      10 REF-Amount         PIC 9(7)V99.
      10 REF-Reason         PIC X(3).
*> Text that may or may not hold a number: test the X view, then
*> compute with the 9 view.
01 Input-Text               PIC X(5) VALUE "00042".
01 Input-Number REDEFINES Input-Text PIC 9(5).
77 Next-Year                PIC 9(4).
77 Doubled                  PIC 9(5).
77 Show-Amount              PIC Z(6)9.99.
PROCEDURE DIVISION.
Main-Paragraph.
    DISPLAY "Text view  : " Order-Date
    DISPLAY "Parts view : " OD-Year "/" OD-Month "/" OD-Day
    ADD 1 TO OD-Year
    DISPLAY "After ADD  : " Order-Date
    MOVE "20241231" TO Order-Date
    COMPUTE Next-Year = OD-Year + 1
    DISPLAY "Year after " OD-Year " is " Next-Year
*> Variant 1: a payment.
    MOVE "P" TO TR-Type
    MOVE SPACES TO TR-Body
    MOVE 10442371 TO PAY-Account
    MOVE 250.00 TO PAY-Amount
    MOVE "CRD" TO PAY-Method
    PERFORM Show-Transaction
*> Variant 2: a refund, written through the other view.
    MOVE "R" TO TR-Type
    MOVE SPACES TO TR-Body
    MOVE "INV-2026-118" TO REF-Original-Ref
    MOVE 75.50 TO REF-Amount
    MOVE "DMG" TO REF-Reason
    PERFORM Show-Transaction
*> Class test on the text view before arithmetic on the numeric view.
    IF Input-Text IS NUMERIC
       COMPUTE Doubled = Input-Number * 2
       DISPLAY "Doubled    : " Doubled
    END-IF
    MOVE "4x2" TO Input-Text
    IF Input-Text IS NOT NUMERIC
       DISPLAY "Not numeric: [" Input-Text "]"
    END-IF
    STOP RUN.

Show-Transaction.
    DISPLAY "Raw        : [" Transaction-Record "]"
    EVALUATE TRUE
       WHEN TR-Is-Payment
          MOVE PAY-Amount TO Show-Amount
          DISPLAY "Payment    : account " PAY-Account
                  " amount " Show-Amount " via " PAY-Method
       WHEN TR-Is-Refund
          MOVE REF-Amount TO Show-Amount
          DISPLAY "Refund     : ref " REF-Original-Ref
                  " amount " Show-Amount " reason " REF-Reason
       WHEN OTHER
          DISPLAY "Unknown type " TR-Type
    END-EVALUATE.