When is Working-Storage allocated?

At program start; variables persist for the entire run unless you use Local-Storage.

Condition-names that create readable boolean states over a data item.

How should I initialize data?

Use VALUE clauses for defaults and INITIALIZE for bulk reset of groups.

COBOL Working Storage Concepts

Working-Storage variables exist for the life of the program. Use it for program state, counters, and buffers. Prefer clear names and reasonable sizes. This section covers data lifetime, initialization, and best practices for Working-Storage.

Declaring and Initializing

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       WORKING-STORAGE SECTION.
       01 TOTAL-COUNT     PIC 9(6) VALUE 0.
       01 RUN-MODE        PIC X     VALUE 'N'.
           88 TEST-MODE VALUE 'T'.
           88 PROD-MODE VALUE 'P'.
       01 BUFFER-AREA     PIC X(200) VALUE SPACES.
       01 LIMITS.
           05 MAX-ROWS      PIC 9(4) VALUE 500.
           05 MAX-AMOUNT    PIC 9(9)V99 VALUE 0.
           05 MIN-AMOUNT    PIC 9(9)V99 VALUE 100.
       01 COUNTERS.
           05 RECORD-COUNT PIC 9(6) VALUE 0.
           05 ERROR-COUNT  PIC 9(4) VALUE 0.
           05 SUCCESS-COUNT PIC 9(6) VALUE 0.

VALUE sets defaults at load time. Use 88-levels for readability instead of magic values. Group related variables together for better organization and maintenance.

Resetting Data

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       INITIALIZE LIMITS REPLACING NUMERIC DATA BY 0
                               ALPHABETIC DATA BY SPACES.
       INITIALIZE COUNTERS REPLACING NUMERIC DATA BY 0.
       MOVE SPACES TO BUFFER-AREA.

INITIALIZE resets groups efficiently. Use REPLACING to specify different values for numeric vs alphabetic data. For individual fields, use MOVE with appropriate values.

Using 88-levels

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       SET TEST-MODE TO TRUE
       IF TEST-MODE
           DISPLAY 'Running in test mode'
           MOVE 10 TO MAX-ROWS
       ELSE IF PROD-MODE
           DISPLAY 'Running in production mode'
           MOVE 1000 TO MAX-ROWS
       END-IF.

88-levels create readable boolean conditions. Use SET to assign values and IF to test conditions. Much clearer than testing for 'T' or 'P' directly.

Memory Management

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       *> Good: reasonable buffer size
       01 INPUT-BUFFER PIC X(1000).
       
       *> Avoid: excessive memory allocation
       01 HUGE-BUFFER PIC X(100000).
       
       *> Better: dynamic sizing with DEPENDING ON
       01 DYNAMIC-TABLE.
           05 TABLE-ENTRY OCCURS 1 TO 1000 TIMES
              DEPENDING ON TABLE-SIZE INDEXED BY TABLE-IX.
               10 ENTRY-DATA PIC X(50).
       01 TABLE-SIZE PIC 9(4) VALUE 0.

Allocate only what you need. Large buffers waste memory and can cause performance issues. Use DEPENDING ON for variable-size tables to save memory.

Lifetime: persists entire program run; survives between procedure calls.
Size: declare just enough; huge buffers waste memory and slow performance.
Clarity: prefer groups for related values; use meaningful names.
Initialization: use VALUE for defaults; INITIALIZE for bulk reset.
88-levels: create readable boolean conditions instead of magic values.

Local Storage Section

Invocation-scoped storage

Condition Names

Readable boolean flags