COBOL Tutorial

COBOL RENAMES Clause - Quick Reference

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Overview

The RENAMES clause creates alternative names for existing fields in COBOL data structures. It provides convenient access to groups of fields without allocating additional storage, making code more readable and maintainable.

Purpose and Usage

Alternative field names - Create convenient names for field groups
Logical groupings - Group related fields together
No storage overhead - Uses existing storage without allocation
Code readability - Improve code clarity and maintainability
Interface compatibility - Provide multiple access patterns

RENAMES vs REDEFINES Concept

RENAMES: [Field1][Field2][Field3] → [Group1] (same storage)

REDEFINES: [Storage Area] → [Layout1] OR [Layout2] (different views)

RENAMES creates aliases, REDEFINES creates alternative layouts

RENAMES provides alternative names without changing storage allocation.

Syntax

The RENAMES clause follows specific syntax patterns within data definitions and can be used to create various field groupings.

Basic Syntax

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* Basic RENAMES clause syntax
66 new-name RENAMES field-name THRU field-name
 
* Complete example
01  CUSTOMER-RECORD.
    05  CUSTOMER-ID       PIC 9(5).
    05  CUSTOMER-NAME     PIC X(30).
    05  CUSTOMER-ADDRESS  PIC X(50).
    05  CUSTOMER-PHONE    PIC X(15).
    05  CUSTOMER-EMAIL    PIC X(40).
 
66  CUSTOMER-CONTACT RENAMES CUSTOMER-PHONE THRU CUSTOMER-EMAIL.
 
* Multiple RENAMES in same structure
01  EMPLOYEE-RECORD.
    05  EMPLOYEE-ID       PIC 9(5).
    05  EMPLOYEE-NAME     PIC X(30).
    05  EMPLOYEE-DEPT     PIC X(10).
    05  EMPLOYEE-SALARY   PIC 9(7)V99.
    05  EMPLOYEE-HIRE-DATE PIC 9(8).
 
66  EMPLOYEE-IDENTITY RENAMES EMPLOYEE-ID THRU EMPLOYEE-NAME.
66  EMPLOYEE-FINANCIAL RENAMES EMPLOYEE-SALARY THRU EMPLOYEE-HIRE-DATE.

RENAMES uses level 66 and creates alternative names for existing fields.

RENAMES vs REDEFINES Comparison

Aspect	RENAMES	REDEFINES
Storage allocation	No additional storage	Shares storage area
Purpose	Alternative names	Alternative layouts
Level number	66	01 or higher
Data interpretation	Same data	Different interpretation
Performance impact	None	None

Complex RENAMES Examples

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* RENAMES with nested structures
01  COMPLEX-RECORD.
    05  HEADER-INFO.
        10  RECORD-TYPE    PIC X.
        10  RECORD-DATE    PIC 9(8).
    05  DETAIL-INFO.
        10  CUSTOMER-DATA.
            15  CUST-ID    PIC 9(5).
            15  CUST-NAME  PIC X(30).
        10  ORDER-DATA.
            15  ORDER-NUM  PIC 9(8).
            15  ORDER-AMT  PIC 9(7)V99.
 
* Multiple RENAMES for different groupings
66  RECORD-HEADER RENAMES HEADER-INFO.
66  CUSTOMER-ORDER RENAMES CUSTOMER-DATA THRU ORDER-DATA.
66  IDENTIFICATION RENAMES CUST-ID THRU CUST-NAME.
66  ORDER-INFORMATION RENAMES ORDER-NUM THRU ORDER-AMT.
 
* RENAMES with arrays
01  ARRAY-RECORD.
    05  RECORD-COUNT      PIC 9(2).
    05  DATA-ARRAY.
        10  DATA-ITEM     PIC X(20) OCCURS 10 TIMES.
 
66  ARRAY-DATA RENAMES DATA-ARRAY.
66  FIRST-ITEM RENAMES DATA-ITEM(1).
66  LAST-ITEM RENAMES DATA-ITEM(10).

RENAMES can create complex groupings of nested structures and arrays.

Practical Examples

These examples demonstrate how to use the RENAMES clause effectively in different programming scenarios.

Customer Data Grouping

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IDENTIFICATION DIVISION.
PROGRAM-ID. CUSTOMER-PROCESS.
 
DATA DIVISION.
WORKING-STORAGE SECTION.
01  CUSTOMER-RECORD.
    05  CUSTOMER-ID       PIC 9(5).
    05  CUSTOMER-NAME     PIC X(30).
    05  CUSTOMER-ADDRESS  PIC X(50).
    05  CUSTOMER-CITY     PIC X(20).
    05  CUSTOMER-STATE    PIC X(2).
    05  CUSTOMER-ZIP      PIC X(10).
    05  CUSTOMER-PHONE    PIC X(15).
    05  CUSTOMER-EMAIL    PIC X(40).
    05  CUSTOMER-BALANCE  PIC 9(7)V99.
    05  CUSTOMER-CREDIT   PIC 9(3).
 
* Create logical groupings
66  CUSTOMER-IDENTITY RENAMES CUSTOMER-ID THRU CUSTOMER-NAME.
66  CUSTOMER-LOCATION RENAMES CUSTOMER-ADDRESS THRU CUSTOMER-ZIP.
66  CUSTOMER-CONTACT RENAMES CUSTOMER-PHONE THRU CUSTOMER-EMAIL.
66  CUSTOMER-FINANCIAL RENAMES CUSTOMER-BALANCE THRU CUSTOMER-CREDIT.
 
PROCEDURE DIVISION.
MAIN-PROCESS.
    * Initialize customer data
    MOVE 12345 TO CUSTOMER-ID
    MOVE "JOHN DOE" TO CUSTOMER-NAME
    MOVE "123 MAIN ST" TO CUSTOMER-ADDRESS
    MOVE "NEW YORK" TO CUSTOMER-CITY
    MOVE "NY" TO CUSTOMER-STATE
    MOVE "10001" TO CUSTOMER-ZIP
    MOVE "555-1234" TO CUSTOMER-PHONE
    MOVE "john@email.com" TO CUSTOMER-EMAIL
    MOVE 1000.00 TO CUSTOMER-BALANCE
    MOVE 750 TO CUSTOMER-CREDIT
    
    * Process using RENAMES groupings
    PERFORM PROCESS-IDENTITY
    PERFORM PROCESS-LOCATION
    PERFORM PROCESS-CONTACT
    PERFORM PROCESS-FINANCIAL
    
    STOP RUN.
 
PROCESS-IDENTITY.
    DISPLAY "Processing Identity: " CUSTOMER-IDENTITY.
 
PROCESS-LOCATION.
    DISPLAY "Processing Location: " CUSTOMER-LOCATION.
 
PROCESS-CONTACT.
    DISPLAY "Processing Contact: " CUSTOMER-CONTACT.
 
PROCESS-FINANCIAL.
    DISPLAY "Processing Financial: " CUSTOMER-FINANCIAL.

RENAMES creates logical groupings for better code organization.

Financial Record Processing

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* Financial transaction record with RENAMES
01  TRANSACTION-RECORD.
    05  TRANS-HEADER.
        10  TRANS-DATE     PIC 9(8).
        10  TRANS-TIME     PIC 9(6).
        10  TRANS-TYPE     PIC X.
    05  TRANS-DETAILS.
        10  ACCOUNT-NUM    PIC 9(10).
        10  TRANS-AMOUNT   PIC 9(7)V99.
        10  TRANS-DESC     PIC X(40).
    05  TRANS-TRAILER.
        10  TRANS-STATUS   PIC X.
        10  TRANS-REF      PIC 9(8).
 
* Create business-oriented groupings
66  TRANSACTION-INFO RENAMES TRANS-HEADER THRU TRANS-TRAILER.
66  TIMESTAMP RENAMES TRANS-DATE THRU TRANS-TIME.
66  ACCOUNT-INFO RENAMES ACCOUNT-NUM THRU TRANS-DESC.
66  TRANSACTION-SUMMARY RENAMES TRANS-AMOUNT THRU TRANS-REF.
 
PROCEDURE DIVISION.
PROCESS-TRANSACTION.
    * Process using different groupings
    IF TRANS-TYPE = "D"
        PERFORM PROCESS-DEPOSIT
    ELSE
        PERFORM PROCESS-WITHDRAWAL
    END-IF
    
    PERFORM VALIDATE-TIMESTAMP
    PERFORM UPDATE-ACCOUNT-INFO.
 
PROCESS-DEPOSIT.
    DISPLAY "Processing deposit: " TRANSACTION-SUMMARY.
 
PROCESS-WITHDRAWAL.
    DISPLAY "Processing withdrawal: " TRANSACTION-SUMMARY.
 
VALIDATE-TIMESTAMP.
    DISPLAY "Validating timestamp: " TIMESTAMP.
 
UPDATE-ACCOUNT-INFO.
    DISPLAY "Updating account: " ACCOUNT-INFO.

RENAMES provides business-oriented groupings for financial data.

Interface Compatibility

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* Legacy record structure
01  LEGACY-RECORD.
    05  L-CUST-ID         PIC 9(5).
    05  L-CUST-NAME       PIC X(30).
    05  L-CUST-ADDR       PIC X(50).
 
* New record structure
01  NEW-RECORD.
    05  CUSTOMER-ID       PIC 9(5).
    05  CUSTOMER-NAME     PIC X(30).
    05  CUSTOMER-ADDRESS  PIC X(50).
    05  CUSTOMER-PHONE    PIC X(15).
    05  CUSTOMER-EMAIL    PIC X(40).
 
* Create compatibility RENAMES
66  LEGACY-COMPATIBLE RENAMES CUSTOMER-ID THRU CUSTOMER-ADDRESS.
 
PROCEDURE DIVISION.
MAINTAIN-COMPATIBILITY.
    * New code can use new field names
    MOVE 12345 TO CUSTOMER-ID
    MOVE "JOHN DOE" TO CUSTOMER-NAME
    MOVE "123 MAIN ST" TO CUSTOMER-ADDRESS
    MOVE "555-1234" TO CUSTOMER-PHONE
    MOVE "john@email.com" TO CUSTOMER-EMAIL
    
    * Legacy code can still access data using RENAMES
    PERFORM LEGACY-PROCESSING.
 
LEGACY-PROCESSING.
    * This procedure expects the old field names
    DISPLAY "Legacy ID: " L-CUST-ID OF LEGACY-COMPATIBLE
    DISPLAY "Legacy Name: " L-CUST-NAME OF LEGACY-COMPATIBLE
    DISPLAY "Legacy Address: " L-CUST-ADDR OF LEGACY-COMPATIBLE.
 
* Alternative: Create multiple interface views
66  IDENTIFICATION-VIEW RENAMES CUSTOMER-ID THRU CUSTOMER-NAME.
66  CONTACT-VIEW RENAMES CUSTOMER-PHONE THRU CUSTOMER-EMAIL.
66  FULL-VIEW RENAMES CUSTOMER-ID THRU CUSTOMER-EMAIL.

RENAMES enables backward compatibility and multiple interface views.

Data Validation Grouping

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* Record with validation groupings
01  VALIDATION-RECORD.
    05  REQUIRED-FIELDS.
        10  CUSTOMER-ID   PIC 9(5).
        10  CUSTOMER-NAME PIC X(30).
        10  CUSTOMER-ADDR PIC X(50).
    05  OPTIONAL-FIELDS.
        10  CUSTOMER-PHONE PIC X(15).
        10  CUSTOMER-EMAIL PIC X(40).
        10  CUSTOMER-NOTE  PIC X(100).
    05  CALCULATED-FIELDS.
        10  CUSTOMER-BALANCE PIC 9(7)V99.
        10  CUSTOMER-CREDIT  PIC 9(3).
 
* Create validation groupings
66  MANDATORY-DATA RENAMES REQUIRED-FIELDS.
66  SUPPLEMENTAL-DATA RENAMES OPTIONAL-FIELDS.
66  COMPUTED-DATA RENAMES CALCULATED-FIELDS.
 
PROCEDURE DIVISION.
VALIDATE-RECORD.
    * Validate required fields
    PERFORM VALIDATE-MANDATORY
    
    * Validate optional fields if present
    IF CUSTOMER-PHONE NOT = SPACES
        PERFORM VALIDATE-SUPPLEMENTAL
    END-IF
    
    * Calculate derived fields
    PERFORM CALCULATE-FIELDS.
 
VALIDATE-MANDATORY.
    IF CUSTOMER-ID = ZERO
        DISPLAY "Error: Customer ID required"
    END-IF
    IF CUSTOMER-NAME = SPACES
        DISPLAY "Error: Customer name required"
    END-IF
    IF CUSTOMER-ADDR = SPACES
        DISPLAY "Error: Customer address required"
    END-IF.
 
VALIDATE-SUPPLEMENTAL.
    DISPLAY "Validating supplemental data: " SUPPLEMENTAL-DATA.
 
CALCULATE-FIELDS.
    * Calculate balance and credit based on business rules
    COMPUTE CUSTOMER-BALANCE = 0
    MOVE 500 TO CUSTOMER-CREDIT
    DISPLAY "Calculated data: " COMPUTED-DATA.

RENAMES creates logical groupings for data validation and processing.

Best Practices and Tips

Following these best practices ensures effective use of the RENAMES clause in COBOL applications.

RENAMES Best Practices

Use meaningful names - Create descriptive RENAMES names
Group related fields - Group fields that are used together
Document the purpose - Add comments explaining RENAMES usage
Maintain consistency - Use consistent naming conventions
Consider maintainability - Make RENAMES easy to understand
Test thoroughly - Verify RENAMES work as expected

Common Pitfalls to Avoid

Pitfall	Problem	Solution
Invalid field references	Compilation errors	Ensure fields exist in structure
Confusing names	Code readability issues	Use clear, descriptive names
Overuse of RENAMES	Code complexity	Use RENAMES judiciously
Inconsistent naming	Maintenance difficulties	Follow naming conventions
Missing documentation	Understanding difficulties	Document RENAMES purpose

Performance Considerations

No storage overhead - RENAMES doesn't allocate additional memory
No runtime impact - Resolved at compile time
Efficient access - Same performance as original field names
Memory efficient - Particularly useful in memory-constrained environments
Compiler optimization - Modern compilers optimize RENAMES efficiently

When to Use RENAMES vs REDEFINES

Scenario	Use RENAMES	Use REDEFINES
Alternative names	Yes	No
Different data layouts	No	Yes
Logical groupings	Yes	No
Union-like structures	No	Yes
Interface compatibility	Yes	Sometimes

RENAMES Clause Quick Reference

Usage	Syntax	Example
Basic RENAMES	66 name RENAMES field THRU field	66 GROUP RENAMES FIELD1 THRU FIELD3
Single field	66 name RENAMES field	66 ALIAS RENAMES FIELD1
Multiple RENAMES	Multiple 66 level entries	66 GROUP1 RENAMES F1 THRU F3 66 GROUP2 RENAMES F4 THRU F6
Nested structures	66 name RENAMES group-field	66 HEADER RENAMES HEADER-GROUP
Array elements	66 name RENAMES array(index)	66 FIRST RENAMES ARRAY(1)

Test Your Knowledge

1. What is the primary purpose of the RENAMES clause in COBOL?

To rename files
To create alternative field groupings
To rename programs
To rename variables

2. In which section is the RENAMES clause most commonly used?

PROCEDURE DIVISION
WORKING-STORAGE SECTION
FILE SECTION
ENVIRONMENT DIVISION

3. What happens when you use RENAMES in a data definition?

New storage is allocated
Alternative names are created for existing fields
Fields are moved to different locations
Data is copied to new fields

4. What is the relationship between RENAMES and REDEFINES?

They are the same thing
RENAMES creates aliases, REDEFINES reuses storage
RENAMES is faster than REDEFINES
They cannot be used together

5. Which of the following is a valid RENAMES clause usage?

RENAMES field-name
RENAMES field-name THRU field-name
RENAMES field-name TO field-name
All of the above

Frequently Asked Questions

Related Concepts

REDEFINES Clause

Understanding the REDEFINES clause for alternative data layouts.

Data Description Entries

Complete guide to data description entries in COBOL.

WORKING-STORAGE SECTION

Understanding the WORKING-STORAGE SECTION.

Data Types

Understanding data types in COBOL.

Structured Programming

Programming principles and techniques.

REMOVAL Clause REORG-CRITERIA Clause

COBOL Tutorial

COBOL RENAMES Clause - Quick Reference

Overview

Purpose and Usage

RENAMES vs REDEFINES Concept

Syntax

Basic Syntax

RENAMES vs REDEFINES Comparison

Complex RENAMES Examples

Practical Examples

Customer Data Grouping

Financial Record Processing

Interface Compatibility

Data Validation Grouping

Best Practices and Tips

RENAMES Best Practices

Common Pitfalls to Avoid

Performance Considerations

When to Use RENAMES vs REDEFINES

RENAMES Clause Quick Reference

Test Your Knowledge

Frequently Asked Questions

What is the difference between RENAMES and REDEFINES in COBOL?

How does the RENAMES clause affect memory usage and performance?

Can you use RENAMES with all data types and field levels in COBOL?

What are some common use cases for the RENAMES clause?

How do you handle errors and debugging when using the RENAMES clause?

Related Concepts

REDEFINES Clause

Data Description Entries

WORKING-STORAGE SECTION

Data Types

Structured Programming

Related Pages