COBOL Tutorial

COBOL Built-in Functions

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Introduction to Built-in Functions

Built-in functions in COBOL provide a powerful set of predefined operations that simplify common programming tasks and improve code efficiency. These intrinsic functions cover a wide range of operations including string manipulation, mathematical calculations, date/time processing, and data conversion, making COBOL programming more productive and maintainable.

Key categories of built-in functions include:

String Functions: LENGTH, TRIM, SUBSTRING, and text manipulation
Mathematical Functions: ABS, SQRT, trigonometric functions
Date/Time Functions: CURRENT-DATE, DATE-OF-INTEGER
Conversion Functions: NUMVAL, CHAR, data type conversion
Utility Functions: RANDOM, MAX, MIN, statistical functions

String Manipulation Functions

String manipulation functions provide essential capabilities for working with text data, including length calculation, trimming, and substring extraction.

Basic String Functions

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IDENTIFICATION DIVISION.
PROGRAM-ID. STRING-FUNCTIONS-DEMO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 STRING-DATA.
   05 WS-INPUT-STRING       PIC X(50) VALUE "  Hello World  ".
   05 WS-NAME-STRING        PIC X(30) VALUE "John Smith".
   05 WS-ADDRESS-STRING     PIC X(50) VALUE "123 Main Street, Anytown, ST 12345".
   05 WS-PHONE-STRING       PIC X(15) VALUE "(555) 123-4567".
 
01 STRING-RESULTS.
   05 WS-STRING-LENGTH      PIC 9(2).
   05 WS-TRIMMED-STRING     PIC X(50).
   05 WS-SUBSTRING-RESULT   PIC X(20).
   05 WS-UPPERCASE-STRING   PIC X(50).
   05 WS-LOWERCASE-STRING   PIC X(50).
 
PROCEDURE DIVISION.
    DISPLAY "=== String Functions Demonstration ==="
    PERFORM DEMONSTRATE-LENGTH-FUNCTION
    PERFORM DEMONSTRATE-TRIM-FUNCTION
    PERFORM DEMONSTRATE-SUBSTRING-FUNCTION
    PERFORM DEMONSTRATE-CASE-FUNCTIONS
    STOP RUN.
 
DEMONSTRATE-LENGTH-FUNCTION.
    DISPLAY "=== LENGTH Function ==="
    DISPLAY "Input string: '" WS-INPUT-STRING "'"
    
    COMPUTE WS-STRING-LENGTH = FUNCTION LENGTH(WS-INPUT-STRING)
    DISPLAY "Length of input string: " WS-STRING-LENGTH
    
    COMPUTE WS-STRING-LENGTH = FUNCTION LENGTH(WS-NAME-STRING)
    DISPLAY "Length of name string: " WS-STRING-LENGTH
    
    COMPUTE WS-STRING-LENGTH = FUNCTION LENGTH(WS-ADDRESS-STRING)
    DISPLAY "Length of address string: " WS-STRING-LENGTH.
 
DEMONSTRATE-TRIM-FUNCTION.
    DISPLAY "=== TRIM Function ==="
    DISPLAY "Original string: '" WS-INPUT-STRING "'"
    
    MOVE FUNCTION TRIM(WS-INPUT-STRING) TO WS-TRIMMED-STRING
    DISPLAY "Trimmed string: '" WS-TRIMMED-STRING "'"
    
    COMPUTE WS-STRING-LENGTH = FUNCTION LENGTH(WS-TRIMMED-STRING)
    DISPLAY "Length after trimming: " WS-STRING-LENGTH.
 
DEMONSTRATE-SUBSTRING-FUNCTION.
    DISPLAY "=== SUBSTRING Function ==="
    DISPLAY "Full name: '" WS-NAME-STRING "'"
    
    * Extract first name (positions 1-4)
    MOVE FUNCTION SUBSTRING(WS-NAME-STRING, 1, 4) TO WS-SUBSTRING-RESULT
    DISPLAY "First name: '" WS-SUBSTRING-RESULT "'"
    
    * Extract last name (positions 6-10)
    MOVE FUNCTION SUBSTRING(WS-NAME-STRING, 6, 5) TO WS-SUBSTRING-RESULT
    DISPLAY "Last name: '" WS-SUBSTRING-RESULT "'".
 
DEMONSTRATE-CASE-FUNCTIONS.
    DISPLAY "=== Case Functions ==="
    DISPLAY "Original string: '" WS-INPUT-STRING "'"
    
    MOVE FUNCTION UPPER-CASE(FUNCTION TRIM(WS-INPUT-STRING)) TO WS-UPPERCASE-STRING
    DISPLAY "Uppercase string: '" WS-UPPERCASE-STRING "'"
    
    MOVE FUNCTION LOWER-CASE(FUNCTION TRIM(WS-INPUT-STRING)) TO WS-LOWERCASE-STRING
    DISPLAY "Lowercase string: '" WS-LOWERCASE-STRING "'".

Mathematical Functions

Mathematical functions provide essential mathematical operations including absolute value, square root, and trigonometric functions.

Basic Mathematical Functions

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IDENTIFICATION DIVISION.
PROGRAM-ID. MATH-FUNCTIONS-DEMO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 MATH-DATA.
   05 WS-NUMBER-1           PIC S9(5)V99 VALUE -123.45.
   05 WS-NUMBER-2           PIC S9(5)V99 VALUE 67.89.
   05 WS-NUMBER-3           PIC S9(5)V99 VALUE 144.00.
   05 WS-ANGLE-DEGREES      PIC S9(3)V99 VALUE 45.00.
 
01 MATH-RESULTS.
   05 WS-ABSOLUTE-VALUE     PIC 9(5)V99.
   05 WS-SQUARE-ROOT        PIC 9(5)V99.
   05 WS-SINE-VALUE         PIC S9V9999.
   05 WS-COSINE-VALUE       PIC S9V9999.
   05 WS-TANGENT-VALUE      PIC S9V9999.
   05 WS-LOGARITHM          PIC 9(5)V99.
   05 WS-POWER-RESULT       PIC 9(8)V99.
 
PROCEDURE DIVISION.
    DISPLAY "=== Mathematical Functions Demonstration ==="
    PERFORM DEMONSTRATE-ABSOLUTE-FUNCTION
    PERFORM DEMONSTRATE-SQUARE-ROOT-FUNCTION
    PERFORM DEMONSTRATE-TRIGONOMETRIC-FUNCTIONS
    PERFORM DEMONSTRATE-LOGARITHM-FUNCTION
    PERFORM DEMONSTRATE-POWER-FUNCTION
    STOP RUN.
 
DEMONSTRATE-ABSOLUTE-FUNCTION.
    DISPLAY "=== ABS Function ==="
    DISPLAY "Original number: " WS-NUMBER-1
    
    COMPUTE WS-ABSOLUTE-VALUE = FUNCTION ABS(WS-NUMBER-1)
    DISPLAY "Absolute value: " WS-ABSOLUTE-VALUE.
 
DEMONSTRATE-SQUARE-ROOT-FUNCTION.
    DISPLAY "=== SQRT Function ==="
    DISPLAY "Number: " WS-NUMBER-3
    
    COMPUTE WS-SQUARE-ROOT = FUNCTION SQRT(WS-NUMBER-3)
    DISPLAY "Square root: " WS-SQUARE-ROOT.
 
DEMONSTRATE-TRIGONOMETRIC-FUNCTIONS.
    DISPLAY "=== Trigonometric Functions ==="
    DISPLAY "Angle: " WS-ANGLE-DEGREES " degrees"
    
    * Convert degrees to radians for trigonometric functions
    COMPUTE WS-SINE-VALUE = FUNCTION SIN(WS-ANGLE-DEGREES * 3.14159 / 180)
    DISPLAY "Sine: " WS-SINE-VALUE
    
    COMPUTE WS-COSINE-VALUE = FUNCTION COS(WS-ANGLE-DEGREES * 3.14159 / 180)
    DISPLAY "Cosine: " WS-COSINE-VALUE
    
    COMPUTE WS-TANGENT-VALUE = FUNCTION TAN(WS-ANGLE-DEGREES * 3.14159 / 180)
    DISPLAY "Tangent: " WS-TANGENT-VALUE.
 
DEMONSTRATE-LOGARITHM-FUNCTION.
    DISPLAY "=== LOG Function ==="
    DISPLAY "Number: " WS-NUMBER-2
    
    COMPUTE WS-LOGARITHM = FUNCTION LOG(WS-NUMBER-2)
    DISPLAY "Natural logarithm: " WS-LOGARITHM.
 
DEMONSTRATE-POWER-FUNCTION.
    DISPLAY "=== ** Power Function ==="
    DISPLAY "Base: " WS-NUMBER-2 ", Exponent: 2"
    
    COMPUTE WS-POWER-RESULT = WS-NUMBER-2 ** 2
    DISPLAY "Power result: " WS-POWER-RESULT.

Date and Time Functions

Date and time functions provide essential capabilities for working with temporal data and performing date calculations.

Date/Time Function Usage

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IDENTIFICATION DIVISION.
PROGRAM-ID. DATE-TIME-FUNCTIONS-DEMO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 DATE-TIME-DATA.
   05 WS-CURRENT-DATE       PIC 9(8).
   05 WS-CURRENT-TIME       PIC 9(6).
   05 WS-CURRENT-DATETIME   PIC 9(14).
   05 WS-TEST-DATE          PIC 9(8) VALUE 20240115.
 
01 DATE-TIME-RESULTS.
   05 WS-DATE-OF-INTEGER    PIC 9(8).
   05 WS-INTEGER-OF-DATE    PIC 9(8).
   05 WS-DAY-OF-WEEK        PIC 9(1).
   05 WS-DAY-OF-YEAR        PIC 9(3).
   05 WS-YEAR-OF-DATE       PIC 9(4).
   05 WS-MONTH-OF-DATE      PIC 9(2).
   05 WS-DAY-OF-DATE        PIC 9(2).
 
PROCEDURE DIVISION.
    DISPLAY "=== Date/Time Functions Demonstration ==="
    PERFORM DEMONSTRATE-CURRENT-DATE-FUNCTION
    PERFORM DEMONSTRATE-DATE-CONVERSION-FUNCTIONS
    PERFORM DEMONSTRATE-DATE-EXTRACTION-FUNCTIONS
    PERFORM DEMONSTRATE-DATE-CALCULATIONS
    STOP RUN.
 
DEMONSTRATE-CURRENT-DATE-FUNCTION.
    DISPLAY "=== CURRENT-DATE Function ==="
    
    ACCEPT WS-CURRENT-DATETIME FROM DATE YYYYMMDD
    ACCEPT WS-CURRENT-DATETIME(9:6) FROM TIME
    
    DISPLAY "Current date/time: " WS-CURRENT-DATETIME
    DISPLAY "Current date: " WS-CURRENT-DATE
    DISPLAY "Current time: " WS-CURRENT-TIME.
 
DEMONSTRATE-DATE-CONVERSION-FUNCTIONS.
    DISPLAY "=== Date Conversion Functions ==="
    DISPLAY "Test date: " WS-TEST-DATE
    
    * Convert date to integer
    COMPUTE WS-INTEGER-OF-DATE = FUNCTION INTEGER-OF-DATE(WS-TEST-DATE)
    DISPLAY "Integer of date: " WS-INTEGER-OF-DATE
    
    * Convert integer back to date
    COMPUTE WS-DATE-OF-INTEGER = FUNCTION DATE-OF-INTEGER(WS-INTEGER-OF-DATE)
    DISPLAY "Date of integer: " WS-DATE-OF-INTEGER.
 
DEMONSTRATE-DATE-EXTRACTION-FUNCTIONS.
    DISPLAY "=== Date Extraction Functions ==="
    DISPLAY "Test date: " WS-TEST-DATE
    
    * Extract year
    COMPUTE WS-YEAR-OF-DATE = FUNCTION YEAR-OF-DATE(WS-TEST-DATE)
    DISPLAY "Year: " WS-YEAR-OF-DATE
    
    * Extract month
    COMPUTE WS-MONTH-OF-DATE = FUNCTION MONTH-OF-DATE(WS-TEST-DATE)
    DISPLAY "Month: " WS-MONTH-OF-DATE
    
    * Extract day
    COMPUTE WS-DAY-OF-DATE = FUNCTION DAY-OF-DATE(WS-TEST-DATE)
    DISPLAY "Day: " WS-DAY-OF-DATE
    
    * Extract day of week
    COMPUTE WS-DAY-OF-WEEK = FUNCTION DAY-OF-WEEK(WS-TEST-DATE)
    DISPLAY "Day of week: " WS-DAY-OF-WEEK
    
    * Extract day of year
    COMPUTE WS-DAY-OF-YEAR = FUNCTION DAY-OF-YEAR(WS-TEST-DATE)
    DISPLAY "Day of year: " WS-DAY-OF-YEAR.
 
DEMONSTRATE-DATE-CALCULATIONS.
    DISPLAY "=== Date Calculations ==="
    
    * Calculate days between dates
    COMPUTE WS-INTEGER-OF-DATE = FUNCTION INTEGER-OF-DATE(WS-TEST-DATE)
    COMPUTE WS-INTEGER-OF-DATE = WS-INTEGER-OF-DATE + 30
    
    COMPUTE WS-DATE-OF-INTEGER = FUNCTION DATE-OF-INTEGER(WS-INTEGER-OF-DATE)
    DISPLAY "Date 30 days later: " WS-DATE-OF-INTEGER.

Data Conversion Functions

Data conversion functions enable transformation between different data types and formats.

Conversion Function Examples

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IDENTIFICATION DIVISION.
PROGRAM-ID. CONVERSION-FUNCTIONS-DEMO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 CONVERSION-DATA.
   05 WS-NUMERIC-STRING     PIC X(10) VALUE "123.45".
   05 WS-CHAR-STRING        PIC X(5) VALUE "HELLO".
   05 WS-NUMERIC-VALUE      PIC 9(5)V99.
   05 WS-CHAR-VALUE         PIC X(1).
 
01 CONVERSION-RESULTS.
   05 WS-CONVERTED-NUMBER   PIC 9(5)V99.
   05 WS-CONVERTED-CHAR     PIC X(1).
   05 WS-VALIDATION-RESULT  PIC X(1).
      88 CONVERSION-VALID   VALUE 'Y'.
      88 CONVERSION-INVALID VALUE 'N'.
 
PROCEDURE DIVISION.
    DISPLAY "=== Conversion Functions Demonstration ==="
    PERFORM DEMONSTRATE-NUMVAL-FUNCTION
    PERFORM DEMONSTRATE-CHAR-FUNCTION
    PERFORM DEMONSTRATE-VALIDATION-FUNCTIONS
    STOP RUN.
 
DEMONSTRATE-NUMVAL-FUNCTION.
    DISPLAY "=== NUMVAL Function ==="
    DISPLAY "Numeric string: '" WS-NUMERIC-STRING "'"
    
    COMPUTE WS-CONVERTED-NUMBER = FUNCTION NUMVAL(WS-NUMERIC-STRING)
    DISPLAY "Converted number: " WS-CONVERTED-NUMBER.
 
DEMONSTRATE-CHAR-FUNCTION.
    DISPLAY "=== CHAR Function ==="
    MOVE 65 TO WS-NUMERIC-VALUE
    DISPLAY "Numeric value: " WS-NUMERIC-VALUE
    
    COMPUTE WS-CONVERTED-CHAR = FUNCTION CHAR(WS-NUMERIC-VALUE)
    DISPLAY "Converted character: '" WS-CONVERTED-CHAR "'".
 
DEMONSTRATE-VALIDATION-FUNCTIONS.
    DISPLAY "=== Validation Functions ==="
    
    * Test numeric validation
    IF FUNCTION NUMVAL-C(WS-NUMERIC-STRING) = 0
       SET CONVERSION-VALID TO TRUE
       DISPLAY "Numeric string is valid"
    ELSE
       SET CONVERSION-INVALID TO TRUE
       DISPLAY "Numeric string is invalid"
    END-IF
    
    * Test character validation
    IF FUNCTION CHAR(65) = "A"
       DISPLAY "Character conversion successful"
    ELSE
       DISPLAY "Character conversion failed"
    END-IF.

Utility and Statistical Functions

Utility and statistical functions provide additional capabilities for data analysis and random number generation.

Utility Function Examples

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IDENTIFICATION DIVISION.
PROGRAM-ID. UTILITY-FUNCTIONS-DEMO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 UTILITY-DATA.
   05 WS-NUMBER-1           PIC 9(3) VALUE 100.
   05 WS-NUMBER-2           PIC 9(3) VALUE 200.
   05 WS-NUMBER-3           PIC 9(3) VALUE 150.
   05 WS-ARRAY OCCURS 10 TIMES.
      10 WS-ARRAY-VALUE      PIC 9(3).
 
01 UTILITY-RESULTS.
   05 WS-MAXIMUM-VALUE      PIC 9(3).
   05 WS-MINIMUM-VALUE      PIC 9(3).
   05 WS-RANDOM-NUMBER      PIC 9(3).
   05 WS-SUM-VALUE          PIC 9(4).
   05 WS-AVERAGE-VALUE      PIC 9(3)V99.
 
PROCEDURE DIVISION.
    DISPLAY "=== Utility Functions Demonstration ==="
    PERFORM INITIALIZE-ARRAY-DATA
    PERFORM DEMONSTRATE-MAX-MIN-FUNCTIONS
    PERFORM DEMONSTRATE-RANDOM-FUNCTION
    PERFORM DEMONSTRATE-STATISTICAL-FUNCTIONS
    STOP RUN.
 
INITIALIZE-ARRAY-DATA.
    DISPLAY "=== Initializing Array Data ==="
    
    MOVE 10 TO WS-ARRAY-VALUE(1)
    MOVE 25 TO WS-ARRAY-VALUE(2)
    MOVE 30 TO WS-ARRAY-VALUE(3)
    MOVE 15 TO WS-ARRAY-VALUE(4)
    MOVE 40 TO WS-ARRAY-VALUE(5)
    MOVE 20 TO WS-ARRAY-VALUE(6)
    MOVE 35 TO WS-ARRAY-VALUE(7)
    MOVE 50 TO WS-ARRAY-VALUE(8)
    MOVE 45 TO WS-ARRAY-VALUE(9)
    MOVE 5 TO WS-ARRAY-VALUE(10)
    
    DISPLAY "Array initialized with values".
 
DEMONSTRATE-MAX-MIN-FUNCTIONS.
    DISPLAY "=== MAX and MIN Functions ==="
    DISPLAY "Numbers: " WS-NUMBER-1 ", " WS-NUMBER-2 ", " WS-NUMBER-3
    
    COMPUTE WS-MAXIMUM-VALUE = FUNCTION MAX(WS-NUMBER-1, WS-NUMBER-2, WS-NUMBER-3)
    DISPLAY "Maximum value: " WS-MAXIMUM-VALUE
    
    COMPUTE WS-MINIMUM-VALUE = FUNCTION MIN(WS-NUMBER-1, WS-NUMBER-2, WS-NUMBER-3)
    DISPLAY "Minimum value: " WS-MINIMUM-VALUE.
 
DEMONSTRATE-RANDOM-FUNCTION.
    DISPLAY "=== RANDOM Function ==="
    
    * Generate random numbers
    PERFORM VARYING WS-NUMBER-1 FROM 1 BY 1
       UNTIL WS-NUMBER-1 > 5
       
       COMPUTE WS-RANDOM-NUMBER = FUNCTION RANDOM(1000)
       DISPLAY "Random number " WS-NUMBER-1 ": " WS-RANDOM-NUMBER
    END-PERFORM.
 
DEMONSTRATE-STATISTICAL-FUNCTIONS.
    DISPLAY "=== Statistical Functions ==="
    
    * Calculate sum of array values
    MOVE 0 TO WS-SUM-VALUE
    PERFORM VARYING WS-NUMBER-1 FROM 1 BY 1
       UNTIL WS-NUMBER-1 > 10
       ADD WS-ARRAY-VALUE(WS-NUMBER-1) TO WS-SUM-VALUE
    END-PERFORM
    
    DISPLAY "Sum of array values: " WS-SUM-VALUE
    
    * Calculate average
    COMPUTE WS-AVERAGE-VALUE = WS-SUM-VALUE / 10
    DISPLAY "Average value: " WS-AVERAGE-VALUE.

Advanced Function Usage

Advanced function usage demonstrates complex scenarios and combinations of built-in functions.

Complex Function Combinations

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IDENTIFICATION DIVISION.
PROGRAM-ID. ADVANCED-FUNCTIONS-DEMO.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 ADVANCED-DATA.
   05 WS-INPUT-TEXT         PIC X(100) VALUE "  Hello World! This is a test.  ".
   05 WS-DATE-STRING        PIC X(10) VALUE "2024-01-15".
   05 WS-PHONE-STRING       PIC X(15) VALUE "(555) 123-4567".
   05 WS-EMAIL-STRING       PIC X(30) VALUE "user@example.com".
 
01 ADVANCED-RESULTS.
   05 WS-PROCESSED-TEXT     PIC X(100).
   05 WS-WORD-COUNT         PIC 9(2).
   05 WS-CLEAN-PHONE        PIC X(10).
   05 WS-DOMAIN-NAME        PIC X(20).
   05 WS-VALIDATION-RESULT  PIC X(1).
 
PROCEDURE DIVISION.
    DISPLAY "=== Advanced Functions Demonstration ==="
    PERFORM DEMONSTRATE-TEXT-PROCESSING
    PERFORM DEMONSTRATE-DATA-CLEANING
    PERFORM DEMONSTRATE-VALIDATION-LOGIC
    STOP RUN.
 
DEMONSTRATE-TEXT-PROCESSING.
    DISPLAY "=== Text Processing ==="
    DISPLAY "Original text: '" WS-INPUT-TEXT "'"
    
    * Process text: trim, convert to uppercase, count words
    MOVE FUNCTION UPPER-CASE(FUNCTION TRIM(WS-INPUT-TEXT)) TO WS-PROCESSED-TEXT
    DISPLAY "Processed text: '" WS-PROCESSED-TEXT "'"
    
    * Count words (simplified approach)
    COMPUTE WS-WORD-COUNT = FUNCTION LENGTH(FUNCTION TRIM(WS-PROCESSED-TEXT)) / 5
    DISPLAY "Estimated word count: " WS-WORD-COUNT.
 
DEMONSTRATE-DATA-CLEANING.
    DISPLAY "=== Data Cleaning ==="
    DISPLAY "Original phone: '" WS-PHONE-STRING "'"
    
    * Extract numeric characters from phone number
    MOVE FUNCTION SUBSTRING(WS-PHONE-STRING, 2, 3) TO WS-CLEAN-PHONE(1:3)
    MOVE FUNCTION SUBSTRING(WS-PHONE-STRING, 7, 3) TO WS-CLEAN-PHONE(4:3)
    MOVE FUNCTION SUBSTRING(WS-PHONE-STRING, 11, 4) TO WS-CLEAN-PHONE(7:4)
    DISPLAY "Cleaned phone: '" WS-CLEAN-PHONE "'"
    
    * Extract domain from email
    DISPLAY "Original email: '" WS-EMAIL-STRING "'"
    MOVE FUNCTION SUBSTRING(WS-EMAIL-STRING, 6, 11) TO WS-DOMAIN-NAME
    DISPLAY "Domain name: '" WS-DOMAIN-NAME "'".
 
DEMONSTRATE-VALIDATION-LOGIC.
    DISPLAY "=== Validation Logic ==="
    
    * Validate email format (simplified)
    IF FUNCTION LENGTH(WS-EMAIL-STRING) > 5 AND
       FUNCTION SUBSTRING(WS-EMAIL-STRING, 5, 1) = "@"
       MOVE 'Y' TO WS-VALIDATION-RESULT
       DISPLAY "Email format appears valid"
    ELSE
       MOVE 'N' TO WS-VALIDATION-RESULT
       DISPLAY "Email format appears invalid"
    END-IF.

Best Practices for Built-in Functions

Following best practices ensures effective and efficient use of built-in functions in COBOL applications.

Usage Guidelines

Use built-in functions instead of custom implementations when possible
Validate input parameters before using functions
Handle function return values appropriately
Combine functions efficiently for complex operations
Document function usage for maintainability

Performance Considerations

Built-in functions are generally optimized for performance
Avoid unnecessary function calls in loops
Cache function results when appropriate
Use appropriate data types for function parameters
Profile function usage in performance-critical sections

Error Handling

Check function return values for expected ranges
Handle division by zero and other mathematical errors
Validate string parameters for length and content
Implement fallback procedures for function failures
Log function errors for debugging and monitoring

FAQ

What are built-in functions in COBOL?

Built-in functions in COBOL are predefined functions provided by the language that perform common operations like string manipulation, mathematical calculations, date/time processing, and data conversion. They are accessed using the FUNCTION keyword and provide efficient, standardized implementations of common operations.

What are the main categories of COBOL built-in functions?

COBOL built-in functions include string functions (LENGTH, TRIM, SUBSTRING), mathematical functions (ABS, SQRT, SIN, COS), date/time functions (CURRENT-DATE, DATE-OF-INTEGER), conversion functions (NUMVAL, CHAR), and utility functions (RANDOM, MAX, MIN).

How do you use built-in functions in COBOL?

Built-in functions are used with the FUNCTION keyword followed by the function name and parameters in parentheses. For example: FUNCTION LENGTH(WS-STRING), FUNCTION ABS(WS-NUMBER), or FUNCTION CURRENT-DATE. They can be used in COMPUTE statements, MOVE statements, and conditional expressions.

What are the performance benefits of built-in functions?

Built-in functions provide optimized implementations, reduce code complexity, improve readability, ensure consistent behavior across platforms, and often perform better than custom implementations. They also reduce the need for external libraries and simplify maintenance.

How do you handle errors with built-in functions?

Built-in functions handle errors through return values (like zero for invalid operations), exception handling mechanisms, and by providing safe default behaviors. It's important to validate input parameters and check return values for expected ranges.

COBOL Tutorial

COBOL Built-in Functions

Introduction to Built-in Functions

String Manipulation Functions

Basic String Functions

Mathematical Functions

Basic Mathematical Functions

Date and Time Functions

Date/Time Function Usage

Data Conversion Functions

Conversion Function Examples

Utility and Statistical Functions

Utility Function Examples

Advanced Function Usage

Complex Function Combinations

Best Practices for Built-in Functions

Usage Guidelines

Performance Considerations

Error Handling

FAQ

What are built-in functions in COBOL?

What are the main categories of COBOL built-in functions?

How do you use built-in functions in COBOL?

What are the performance benefits of built-in functions?

How do you handle errors with built-in functions?

Arithmetic Operations

String Processing

Date Time Handling

Data Conversion