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COBOL Tutorial

COBOL VALUE OF - Quick Reference

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Overview

VALUE OF is a COBOL clause used to assign initial values to data items when they are declared. It allows you to specify default values for variables, making programs more predictable and reducing the need for explicit initialization in the PROCEDURE DIVISION.

Purpose and Usage

  • Data initialization at declaration time
  • Default value assignment
  • Predictable program behavior
  • Reduced initialization code
  • Cleaner program structure

Syntax

VALUE OF follows specific syntax patterns in data declarations:

Basic Syntax

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* Basic VALUE OF syntax
01  counter PIC 9(4) VALUE 0.
01  status-flag PIC X VALUE "N".
01  total-amount PIC 9(8)V99 VALUE 0.00.
01  company-name PIC X(30) VALUE "ACME CORPORATION".
01  active-status PIC X VALUE "Y".
 
* VALUE OF with different data types
01  numeric-field PIC 9(5) VALUE 12345.
01  alphabetic-field PIC A(10) VALUE "HELLO".
01  alphanumeric-field PIC X(15) VALUE "TEST DATA".
01  decimal-field PIC 9(3)V99 VALUE 123.45.

VALUE OF assigns initial values to data items at declaration time.

Group Item Initialization

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* VALUE OF with group items
01  customer-record.
    05  customer-id PIC 9(6) VALUE 0.
    05  customer-name PIC X(30) VALUE SPACES.
    05  customer-status PIC X VALUE "A".
    05  customer-balance PIC 9(8)V99 VALUE 0.00.
 
* VALUE OF with arrays
01  month-names.
    05  month OCCURS 12 TIMES PIC X(9).
        88  january VALUE "JANUARY".
        88  february VALUE "FEBRUARY".
        88  march VALUE "MARCH".
        * ... other months
 
* VALUE OF with figurative constants
01  empty-string PIC X(50) VALUE SPACES.
01  zero-counter PIC 9(4) VALUE ZERO.
01  high-value PIC X(10) VALUE HIGH-VALUES.
01  low-value PIC X(10) VALUE LOW-VALUES.

Practical Examples

Here are some practical uses of VALUE OF in COBOL:

Counter and Accumulator Initialization

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* Counter and accumulator initialization
DATA DIVISION.
WORKING-STORAGE SECTION.
01  processing-stats.
    05  records-processed PIC 9(6) VALUE 0.
    05  records-valid PIC 9(6) VALUE 0.
    05  records-invalid PIC 9(6) VALUE 0.
    05  total-amount PIC 9(10)V99 VALUE 0.00.
01  status-flags.
    05  file-open PIC X VALUE "N".
    05  processing-complete PIC X VALUE "N".
    05  error-occurred PIC X VALUE "N".
 
PROCEDURE DIVISION.
MAIN-PROCESS.
    * Counters are already initialized
    DISPLAY "Starting processing...".
    DISPLAY "Initial record count: " records-processed.
    
    * Process records
    PERFORM UNTIL end-of-file
        READ input-file
            AT END
                MOVE "Y" TO end-of-file-flag
            NOT AT END
                ADD 1 TO records-processed
                PERFORM process-record
        END-READ
    END-PERFORM.
    
    * Display final statistics
    DISPLAY "Records processed: " records-processed.
    DISPLAY "Valid records: " records-valid.
    DISPLAY "Invalid records: " records-invalid.
    DISPLAY "Total amount: " total-amount.
    
    STOP RUN.

Counters and accumulators initialized with VALUE OF.

Configuration and Default Values

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* Configuration and default values
DATA DIVISION.
WORKING-STORAGE SECTION.
01  program-config.
    05  max-records PIC 9(6) VALUE 10000.
    05  batch-size PIC 9(4) VALUE 100.
    05  timeout-seconds PIC 9(3) VALUE 30.
    05  debug-mode PIC X VALUE "N".
01  default-values.
    05  default-currency PIC X(3) VALUE "USD".
    05  default-country PIC X(2) VALUE "US".
    05  default-language PIC X(2) VALUE "EN".
01  system-constants.
    05  company-name PIC X(30) VALUE "MAINFRAME MASTERS".
    05  program-version PIC X(10) VALUE "1.0.0".
    05  copyright-year PIC 9(4) VALUE 2024.
 
PROCEDURE DIVISION.
INITIALIZE-PROGRAM.
    * Configuration is already set
    DISPLAY "Program: " program-version.
    DISPLAY "Company: " company-name.
    DISPLAY "Max records: " max-records.
    DISPLAY "Batch size: " batch-size.
    
    * Use configuration values
    IF debug-mode = "Y"
        DISPLAY "Debug mode enabled"
    END-IF.
    
    PERFORM process-batch.
    
    STOP RUN.
 
PROCESS-BATCH.
    * Use batch size from configuration
    PERFORM UNTIL batch-counter >= batch-size
        * Process batch logic
        ADD 1 TO batch-counter
    END-PERFORM.

Configuration and default values using VALUE OF.

Best Practices

  • Use VALUE OF to initialize all data items with meaningful default values.
  • Use figurative constants like SPACES, ZERO, and HIGH-VALUES when appropriate.
  • Initialize counters and accumulators to zero or appropriate starting values.
  • Use VALUE OF for configuration data and constants.
  • Document the meaning of initial values in comments.
  • Consider the impact of initialization on program performance.

Common Pitfalls

  • Not initializing data items, leading to unpredictable behavior.
  • Using inappropriate initial values for the data type.
  • Forgetting to initialize counters and accumulators.
  • Using VALUE OF with incompatible data types.
  • Not considering the impact of initialization on memory usage.

Test Your Knowledge

1. What is VALUE OF in COBOL?

  • A data type
  • A value assignment clause
  • A file operation
  • A program structure

2. Where is VALUE OF typically used?

  • In the PROCEDURE DIVISION
  • In the DATA DIVISION
  • In the ENVIRONMENT DIVISION
  • In the WORKING-STORAGE SECTION

3. What is the primary purpose of VALUE OF?

  • To perform calculations
  • To assign initial values to data items
  • To read files
  • To display output

4. Can VALUE OF be used with all data types?

  • Yes, always
  • No, only with numeric data
  • No, only with alphanumeric data
  • It depends on the COBOL implementation

5. When is the VALUE OF assignment made?

  • At runtime
  • At compile time
  • When the program starts
  • When the data item is first used

Frequently Asked Questions

Related Concepts

Data Declaration

Understanding data declaration in COBOL.

Initialization

Data initialization techniques in COBOL.

Working Storage

Working storage section usage.

Data Types

COBOL data types and their usage.

Program Structure

Understanding COBOL program structure.

USE AFTER STANDARD EXCEPTION PROCEDUREWITH NO ADVANCING