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COBOL Tutorial

COBOL ZERO - Quick Reference

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Overview

ZERO in COBOL is a figurative constant that represents the numeric value zero. It is used for initializing variables, performing comparisons, and representing zero in calculations. ZERO is the singular form of the zero constant, with ZEROS and ZEROES being the plural forms, though all represent the same value.

Key Features

  • Numeric constant - Represents the numeric value zero
  • Initialization - Used to initialize numeric variables
  • Comparisons - Used in conditional statements and comparisons
  • Arithmetic operations - Can be used in mathematical calculations

Syntax and Usage

ZERO usage patterns for initialization, comparisons, and calculations.

Basic ZERO Initialization

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. ZERO-INITIALIZATION.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  COUNTER        PIC 9(4) VALUE ZERO.
       01  ACCUMULATOR    PIC 9(8) VALUE ZERO.
       01  TOTAL-AMOUNT   PIC 9(10)V99 VALUE ZERO.
       01  ITEM-COUNT     PIC 9(3) VALUE ZERO.
       
       PROCEDURE DIVISION.
           DISPLAY "Counter: " COUNTER
           DISPLAY "Accumulator: " ACCUMULATOR
           DISPLAY "Total Amount: " TOTAL-AMOUNT
           DISPLAY "Item Count: " ITEM-COUNT
           STOP RUN.

Basic ZERO initialization of numeric variables.

ZERO in Comparisons

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. ZERO-COMPARISONS.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  AMOUNT         PIC 9(6)V99 VALUE 150.75.
       01  BALANCE        PIC 9(8)V99 VALUE ZERO.
       01  TRANSACTION-COUNT PIC 9(4) VALUE 0.
       
       PROCEDURE DIVISION.
           * Check if amount is zero
           IF AMOUNT = ZERO
               DISPLAY "Amount is zero"
           ELSE
               DISPLAY "Amount is not zero: " AMOUNT
           END-IF
           
           * Check if balance is zero
           IF BALANCE = ZERO
               DISPLAY "Balance is zero"
           ELSE
               DISPLAY "Balance is not zero: " BALANCE
           END-IF
           
           * Check if transaction count is zero
           IF TRANSACTION-COUNT = ZERO
               DISPLAY "No transactions processed"
           ELSE
               DISPLAY "Transactions processed: " TRANSACTION-COUNT
           END-IF
           
           STOP RUN.

ZERO usage in conditional statements and comparisons.

ZERO in Arithmetic Operations

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. ZERO-ARITHMETIC.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  VALUE-1        PIC 9(4) VALUE 100.
       01  VALUE-2        PIC 9(4) VALUE ZERO.
       01  RESULT         PIC 9(6).
       01  QUOTIENT       PIC 9(6).
       01  REMAINDER      PIC 9(4).
       
       PROCEDURE DIVISION.
           * Addition with ZERO
           ADD ZERO TO VALUE-1 GIVING RESULT
           DISPLAY "Value + ZERO = " RESULT
           
           * Subtraction with ZERO
           SUBTRACT ZERO FROM VALUE-1 GIVING RESULT
           DISPLAY "Value - ZERO = " RESULT
           
           * Multiplication with ZERO
           MULTIPLY VALUE-1 BY ZERO GIVING RESULT
           DISPLAY "Value * ZERO = " RESULT
           
           * Division by ZERO (error handling)
           IF VALUE-2 = ZERO
               DISPLAY "Cannot divide by ZERO"
           ELSE
               DIVIDE VALUE-1 BY VALUE-2 GIVING QUOTIENT REMAINDER REMAINDER
               DISPLAY "Division result: " QUOTIENT
           END-IF
           
           STOP RUN.

ZERO usage in arithmetic operations with error handling.

Usage Patterns

Variable Initialization

Initialize numeric variables to zero.

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01  COUNTER    PIC 9(4) VALUE ZERO.
01  TOTAL      PIC 9(8)V99 VALUE ZERO.
01  BALANCE    PIC S9(10)V99 VALUE ZERO.

Conditional Checks

Check if values are zero.

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IF AMOUNT = ZERO
    DISPLAY "Amount is zero"
END-IF
 
IF BALANCE NOT = ZERO
    PERFORM PROCESS-BALANCE
END-IF

Arithmetic Operations

Use ZERO in calculations.

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ADD ZERO TO TOTAL
MULTIPLY VALUE BY ZERO GIVING RESULT
IF DIVISOR = ZERO
    DISPLAY "Division by zero error"
END-IF

Loop Control

Use ZERO for loop initialization.

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MOVE ZERO TO LOOP-COUNTER
PERFORM UNTIL LOOP-COUNTER >= MAX-COUNT
    ADD 1 TO LOOP-COUNTER
    PERFORM PROCESS-ITEM
END-PERFORM

Best Practices

  • Initialization - Use ZERO to initialize numeric variables
  • Readability - Use ZERO instead of literal 0 for better code readability
  • Error handling - Check for division by ZERO to prevent runtime errors
  • Consistency - Use ZERO consistently throughout your program
  • Documentation - ZERO makes code self-documenting

ZERO Quick Reference

UsageSyntaxPurpose
InitializationVALUE ZEROInitialize variables to zero
ComparisonIF X = ZEROCheck if value equals zero
ArithmeticADD ZERO TO XUse in calculations
Error CheckIF DIVISOR = ZEROPrevent division by zero

Test Your Knowledge

1. What is the primary purpose of ZERO in COBOL?

  • To represent the numeric value zero in calculations and comparisons
  • To generate random numbers
  • To format output
  • To handle text strings

2. How does ZERO compare to ZEROS and ZEROES in COBOL?

  • ZERO is the singular form, ZEROS and ZEROES are plural forms
  • They are all exactly the same
  • ZERO is faster than ZEROS and ZEROES
  • ZERO only works with integers

3. What is the main use case for ZERO in COBOL?

  • To generate random numbers
  • To initialize variables, perform comparisons, and represent zero in calculations
  • To format output strings
  • To handle text processing

4. How does ZERO behave in arithmetic operations?

  • It causes errors in all operations
  • It behaves as the numeric value zero in all arithmetic operations
  • It only works in addition
  • It only works in subtraction

5. What is a common use case for ZERO in COBOL programs?

  • To generate random numbers
  • To initialize counters, accumulators, and perform zero-based comparisons
  • To format output
  • To handle text strings

Frequently Asked Questions

Related Concepts

ZEROS

Plural form of ZERO constant.

ZEROES

Alternative plural form of ZERO constant.

Numeric Operations

Basic arithmetic operations in COBOL.

Data Types

COBOL data types and their usage.

Variable Initialization

Data description and variable initialization.

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