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COBOL Data Conversion

Data conversion transforms data between different types and formats. Learn to convert between numeric and character formats, change data representations, and handle format transformations in COBOL programs.

Numeric to Character Conversion

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       WORKING-STORAGE SECTION.
       01 NUMERIC-FIELD PIC 9(6) VALUE 123456.
       01 CHARACTER-FIELD PIC X(6).
       01 FORMATTED-FIELD PIC X(10).
       
       PROCEDURE DIVISION.
       *> Basic numeric to character conversion
       MOVE NUMERIC-FIELD TO CHARACTER-FIELD
       DISPLAY 'Numeric as character: ' CHARACTER-FIELD
       
       *> Formatted conversion with editing
       MOVE NUMERIC-FIELD TO FORMATTED-FIELD
       DISPLAY 'Formatted: ' FORMATTED-FIELD
       
       *> Using intrinsic functions
       MOVE FUNCTION NUMVAL(NUMERIC-FIELD) TO CHARACTER-FIELD.

Convert numeric fields to character format using MOVE statements. COBOL automatically handles the conversion based on the target field's PICTURE clause. Use editing characters for formatted output.

Character to Numeric Conversion

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       WORKING-STORAGE SECTION.
       01 CHARACTER-FIELD PIC X(6) VALUE '123456'.
       01 NUMERIC-FIELD PIC 9(6).
       01 VALIDATION-FLAG PIC X VALUE 'N'.
       
       PROCEDURE DIVISION.
       *> Validate before conversion
       IF CHARACTER-FIELD IS NUMERIC
           MOVE CHARACTER-FIELD TO NUMERIC-FIELD
           MOVE 'Y' TO VALIDATION-FLAG
           DISPLAY 'Converted to numeric: ' NUMERIC-FIELD
       ELSE
           DISPLAY 'Error: Non-numeric data in character field'
       END-IF.
       
       *> Using intrinsic functions
       IF FUNCTION NUMVAL(CHARACTER-FIELD) > 0
           MOVE FUNCTION NUMVAL(CHARACTER-FIELD) TO NUMERIC-FIELD
       END-IF.

Convert character fields to numeric format after validating the data. Use class conditions to check if character data is numeric before conversion. Use intrinsic functions for more complex conversions.

Numeric Format Conversion

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       WORKING-STORAGE SECTION.
       01 DISPLAY-NUMERIC PIC 9(6) VALUE 123456.
       01 COMP-NUMERIC PIC 9(6) COMP.
       01 COMP3-NUMERIC PIC 9(6) COMP-3.
       01 COMP5-NUMERIC PIC 9(6) COMP-5.
       
       PROCEDURE DIVISION.
       *> Convert between numeric formats
       MOVE DISPLAY-NUMERIC TO COMP-NUMERIC
       DISPLAY 'DISPLAY to COMP: ' COMP-NUMERIC
       
       MOVE COMP-NUMERIC TO COMP3-NUMERIC
       DISPLAY 'COMP to COMP-3: ' COMP3-NUMERIC
       
       MOVE COMP3-NUMERIC TO COMP5-NUMERIC
       DISPLAY 'COMP-3 to COMP-5: ' COMP5-NUMERIC
       
       *> Convert back to display format
       MOVE COMP5-NUMERIC TO DISPLAY-NUMERIC
       DISPLAY 'COMP-5 to DISPLAY: ' DISPLAY-NUMERIC.

Convert between different numeric formats: DISPLAY (character), COMP (binary), COMP-3 (packed decimal), and COMP-5 (native binary). Each format has different storage requirements and performance characteristics.

Date Format Conversion

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       WORKING-STORAGE SECTION.
       01 YYYYMMDD-DATE PIC 9(8) VALUE 20231225.
       01 MMDDYYYY-DATE PIC X(10).
       01 DDMMYYYY-DATE PIC X(10).
       01 DISPLAY-DATE PIC X(12).
       
       PROCEDURE DIVISION.
       *> Convert YYYYMMDD to MM/DD/YYYY
       STRING YYYYMMDD-DATE(5:2) '/' 
              YYYYMMDD-DATE(7:2) '/' 
              YYYYMMDD-DATE(1:4)
           INTO MMDDYYYY-DATE
       END-STRING
       
       *> Convert YYYYMMDD to DD/MM/YYYY
       STRING YYYYMMDD-DATE(7:2) '/' 
              YYYYMMDD-DATE(5:2) '/' 
              YYYYMMDD-DATE(1:4)
           INTO DDMMYYYY-DATE
       END-STRING
       
       *> Convert to readable format
       STRING YYYYMMDD-DATE(5:2) '/' 
              YYYYMMDD-DATE(7:2) '/' 
              YYYYMMDD-DATE(1:4)
           INTO DISPLAY-DATE
       END-STRING.

Convert date formats using reference modification and STRING statements. Transform between YYYYMMDD, MM/DD/YYYY, DD/MM/YYYY, and other date formats for different display and processing requirements.

Case Conversion

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       WORKING-STORAGE SECTION.
       01 MIXED-CASE PIC X(20) VALUE 'Hello World'.
       01 UPPER-CASE PIC X(20).
       01 LOWER-CASE PIC X(20).
       
       PROCEDURE DIVISION.
       *> Convert to uppercase
       MOVE FUNCTION UPPER-CASE(MIXED-CASE) TO UPPER-CASE
       DISPLAY 'Uppercase: ' UPPER-CASE
       
       *> Convert to lowercase
       MOVE FUNCTION LOWER-CASE(MIXED-CASE) TO LOWER-CASE
       DISPLAY 'Lowercase: ' LOWER-CASE
       
       *> Convert specific portions
       MOVE FUNCTION UPPER-CASE(MIXED-CASE(1:5)) TO UPPER-CASE(1:5)
       DISPLAY 'Partial uppercase: ' UPPER-CASE.

Convert character case using intrinsic functions UPPER-CASE and LOWER-CASE. These functions handle mixed-case text and can be applied to entire fields or specific portions using reference modification.

Currency Format Conversion

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       WORKING-STORAGE SECTION.
       01 AMOUNT PIC 9(9)V99 VALUE 123456789.
       01 CURRENCY-DISPLAY PIC X(15).
       01 CURRENCY-SYMBOL PIC X VALUE '$'.
       
       PROCEDURE DIVISION.
       *> Convert to currency format
       STRING CURRENCY-SYMBOL 
              AMOUNT(1:3) ',' 
              AMOUNT(4:3) ',' 
              AMOUNT(7:3) '.' 
              AMOUNT(10:2)
           INTO CURRENCY-DISPLAY
       END-STRING
       
       DISPLAY 'Currency format: ' CURRENCY-DISPLAY
       
       *> Alternative using editing
       01 EDITED-AMOUNT PIC $,$$$,$$9.99.
       MOVE AMOUNT TO EDITED-AMOUNT
       DISPLAY 'Edited amount: ' EDITED-AMOUNT.

Convert numeric amounts to currency format with symbols, commas, and decimal places. Use STRING statements for custom formatting or PICTURE editing characters for standard currency display.

Data Type Validation

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       VALIDATE-AND-CONVERT.
           *> Validate numeric data
           IF INPUT-FIELD IS NUMERIC
               MOVE INPUT-FIELD TO NUMERIC-FIELD
               DISPLAY 'Valid numeric conversion'
           ELSE
               DISPLAY 'Error: Non-numeric data'
               MOVE 0 TO NUMERIC-FIELD
           END-IF.
           
           *> Validate alphabetic data
           IF NAME-FIELD IS ALPHABETIC
               MOVE FUNCTION UPPER-CASE(NAME-FIELD) TO UPPER-NAME
               DISPLAY 'Valid alphabetic conversion'
           ELSE
               DISPLAY 'Error: Non-alphabetic data in name field'
               MOVE SPACES TO UPPER-NAME
           END-IF.
           
           *> Validate date format
           IF DATE-FIELD IS NUMERIC AND FUNCTION LENGTH(DATE-FIELD) = 8
               MOVE DATE-FIELD TO VALID-DATE
               DISPLAY 'Valid date format'
           ELSE
               DISPLAY 'Error: Invalid date format'
               MOVE 0 TO VALID-DATE
           END-IF.

Validate data before conversion to ensure data integrity. Check data types, lengths, and formats before performing conversions. Provide meaningful error messages and default values for invalid data.

Performance Considerations

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       *> Efficient conversion patterns
       *> Use COMP fields for calculations
       01 CALCULATION-FIELD PIC 9(9)V99 COMP.
       01 DISPLAY-FIELD PIC 9(9)V99.
       
       *> Convert only when needed
       IF DISPLAY-REQUIRED = 'Y'
           MOVE CALCULATION-FIELD TO DISPLAY-FIELD
           DISPLAY 'Amount: ' DISPLAY-FIELD
       END-IF.
       
       *> Batch conversions for efficiency
       PERFORM CONVERT-BATCH-DATA
           VARYING I FROM 1 BY 1 UNTIL I > RECORD-COUNT
           MOVE NUMERIC-DATA(I) TO CHARACTER-DATA(I)
       END-PERFORM.

Optimize conversion performance by using appropriate data types for calculations, converting only when necessary, and batching conversions for efficiency. Consider memory usage and processing time for large datasets.

Data Types

COBOL data types and representations

Data Formatting

Data formatting techniques