MainframeMaster

COBOL Comparison Operations

Comparison operations in COBOL are fundamental to program logic and decision-making. They allow programs to compare values, make decisions, and control program flow based on data relationships. Understanding comparison operations is essential for implementing business logic, data validation, and conditional processing in COBOL programs.

Understanding Comparison Operations

Comparison operations in COBOL evaluate the relationship between two values and return a true or false result. These operations are used in IF statements, EVALUATE clauses, and other conditional logic to control program flow. COBOL supports various relational operators for different types of comparisons.

Relational Operators

1. Basic Relational Operators

COBOL provides six basic relational operators for comparing values. These operators work with both numeric and alphanumeric data, though the comparison behavior differs based on the data type being compared.

cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
       IDENTIFICATION DIVISION.
       PROGRAM-ID. RELATIONAL-OPERATORS-EXAMPLE.
       *> This program demonstrates basic relational operators in COBOL
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       *> Test data for relational operator demonstrations
       01 NUMERIC-COMPARISON-DATA.
           05 FIRST-NUMBER        PIC 9(3) VALUE 100.
           05 SECOND-NUMBER       PIC 9(3) VALUE 200.
           05 THIRD-NUMBER        PIC 9(3) VALUE 100.
           05 FOURTH-NUMBER       PIC 9(3) VALUE 50.
       
       01 CHARACTER-COMPARISON-DATA.
           05 FIRST-STRING        PIC X(10) VALUE 'APPLE'.
           05 SECOND-STRING       PIC X(10) VALUE 'BANANA'.
           05 THIRD-STRING        PIC X(10) VALUE 'APPLE'.
           05 FOURTH-STRING       PIC X(10) VALUE 'CHERRY'.
       
       01 COMPARISON-RESULTS.
           05 RESULT-STATUS       PIC X(1).
               88 COMPARISON-TRUE VALUE 'T'.
               88 COMPARISON-FALSE VALUE 'F'.
       
       PROCEDURE DIVISION.
       DEMONSTRATE-RELATIONAL-OPERATORS.
           DISPLAY 'Demonstrating COBOL Relational Operators'
           DISPLAY '========================================'
           
       *> Demonstrate numeric comparisons
           PERFORM DEMONSTRATE-NUMERIC-COMPARISONS
           
       *> Demonstrate character comparisons
           PERFORM DEMONSTRATE-CHARACTER-COMPARISONS
           
           STOP RUN.
       
       DEMONSTRATE-NUMERIC-COMPARISONS.
           DISPLAY 'Numeric Comparisons:'
           DISPLAY 'First Number: ' FIRST-NUMBER
           DISPLAY 'Second Number: ' SECOND-NUMBER
           DISPLAY 'Third Number: ' THIRD-NUMBER
           DISPLAY 'Fourth Number: ' FOURTH-NUMBER
           DISPLAY ' '
           
       *> Equal comparison (=)
           IF FIRST-NUMBER = THIRD-NUMBER
               DISPLAY '100 = 100 (TRUE) - Equal comparison'
           ELSE
               DISPLAY '100 = 100 (FALSE) - Equal comparison'
           END-IF
           
       *> Not equal comparison (NOT =)
           IF FIRST-NUMBER NOT = SECOND-NUMBER
               DISPLAY '100 NOT = 200 (TRUE) - Not equal comparison'
           ELSE
               DISPLAY '100 NOT = 200 (FALSE) - Not equal comparison'
           END-IF
           
       *> Greater than comparison (>)
           IF SECOND-NUMBER > FIRST-NUMBER
               DISPLAY '200 > 100 (TRUE) - Greater than comparison'
           ELSE
               DISPLAY '200 > 100 (FALSE) - Greater than comparison'
           END-IF
           
       *> Less than comparison (<)
           IF FOURTH-NUMBER < FIRST-NUMBER
               DISPLAY '50 < 100 (TRUE) - Less than comparison'
           ELSE
               DISPLAY '50 < 100 (FALSE) - Less than comparison'
           END-IF
           
       *> Greater than or equal comparison (>=)
           IF FIRST-NUMBER >= THIRD-NUMBER
               DISPLAY '100 >= 100 (TRUE) - Greater than or equal comparison'
           ELSE
               DISPLAY '100 >= 100 (FALSE) - Greater than or equal comparison'
           END-IF
           
       *> Less than or equal comparison (<=)
           IF FOURTH-NUMBER <= FIRST-NUMBER
               DISPLAY '50 <= 100 (TRUE) - Less than or equal comparison'
           ELSE
               DISPLAY '50 <= 100 (FALSE) - Less than or equal comparison'
           END-IF.
       
       DEMONSTRATE-CHARACTER-COMPARISONS.
           DISPLAY 'Character String Comparisons:'
           DISPLAY 'First String: ' FIRST-STRING
           DISPLAY 'Second String: ' SECOND-STRING
           DISPLAY 'Third String: ' THIRD-STRING
           DISPLAY 'Fourth String: ' FOURTH-STRING
           DISPLAY ' '
           
       *> Equal comparison for strings
           IF FIRST-STRING = THIRD-STRING
               DISPLAY 'APPLE = APPLE (TRUE) - String equal comparison'
           ELSE
               DISPLAY 'APPLE = APPLE (FALSE) - String equal comparison'
           END-IF
           
       *> Not equal comparison for strings
           IF FIRST-STRING NOT = SECOND-STRING
               DISPLAY 'APPLE NOT = BANANA (TRUE) - String not equal comparison'
           ELSE
               DISPLAY 'APPLE NOT = BANANA (FALSE) - String not equal comparison'
           END-IF
           
       *> Greater than comparison for strings (alphabetical order)
           IF SECOND-STRING > FIRST-STRING
               DISPLAY 'BANANA > APPLE (TRUE) - String greater than comparison'
           ELSE
               DISPLAY 'BANANA > APPLE (FALSE) - String greater than comparison'
           END-IF
           
       *> Less than comparison for strings (alphabetical order)
           IF FIRST-STRING < SECOND-STRING
               DISPLAY 'APPLE < BANANA (TRUE) - String less than comparison'
           ELSE
               DISPLAY 'APPLE < BANANA (FALSE) - String less than comparison'
           END-IF
           
       *> Greater than or equal comparison for strings
           IF FIRST-STRING >= THIRD-STRING
               DISPLAY 'APPLE >= APPLE (TRUE) - String greater than or equal comparison'
           ELSE
               DISPLAY 'APPLE >= APPLE (FALSE) - String greater than or equal comparison'
           END-IF
           
       *> Less than or equal comparison for strings
           IF FIRST-STRING <= FOURTH-STRING
               DISPLAY 'APPLE <= CHERRY (TRUE) - String less than or equal comparison'
           ELSE
               DISPLAY 'APPLE <= CHERRY (FALSE) - String less than or equal comparison'
           END-IF.

This example demonstrates all six basic relational operators in COBOL: equal (=), not equal (NOT =), greater than (>), less than (<), greater than or equal (>=), and less than or equal (<=). The program shows how these operators work with both numeric and character data. For numeric data, comparisons are based on numeric values, while for character data, comparisons are based on the collating sequence (alphabetical order).

2. Advanced Comparison Techniques

Advanced comparison techniques include using condition names, complex logical expressions, and specialized comparison functions. These techniques provide more sophisticated ways to evaluate conditions and make decisions in COBOL programs.

cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
       IDENTIFICATION DIVISION.
       PROGRAM-ID. ADVANCED-COMPARISON-TECHNIQUES.
       *> This program demonstrates advanced comparison techniques
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       *> Data for advanced comparison demonstrations
       01 CUSTOMER-DATA.
           05 CUSTOMER-ID         PIC 9(8) VALUE 12345678.
           05 CUSTOMER-AGE        PIC 9(3) VALUE 25.
           05 CUSTOMER-INCOME     PIC 9(8)V99 VALUE 50000.00.
           05 CUSTOMER-CREDIT-SCORE PIC 9(3) VALUE 750.
           05 CUSTOMER-STATUS     PIC X(1) VALUE 'A'.
               88 ACTIVE-CUSTOMER VALUE 'A'.
               88 INACTIVE-CUSTOMER VALUE 'I'.
               88 SUSPENDED-CUSTOMER VALUE 'S'.
       
       01 ACCOUNT-DATA.
           05 ACCOUNT-BALANCE     PIC 9(10)V99 VALUE 2500.00.
           05 ACCOUNT-LIMIT       PIC 9(10)V99 VALUE 10000.00.
           05 ACCOUNT-TYPE        PIC X(1) VALUE 'C'.
               88 CHECKING-ACCOUNT VALUE 'C'.
               88 SAVINGS-ACCOUNT VALUE 'S'.
               88 BUSINESS-ACCOUNT VALUE 'B'.
       
       01 TRANSACTION-DATA.
           05 TRANSACTION-AMOUNT  PIC 9(8)V99 VALUE 500.00.
           05 TRANSACTION-TYPE    PIC X(1) VALUE 'D'.
               88 DEPOSIT-TRANSACTION VALUE 'D'.
               88 WITHDRAWAL-TRANSACTION VALUE 'W'.
               88 TRANSFER-TRANSACTION VALUE 'T'.
       
       01 COMPARISON-RESULTS.
           05 VALIDATION-STATUS   PIC X(1).
               88 VALIDATION-PASSED VALUE 'P'.
               88 VALIDATION-FAILED VALUE 'F'.
           05 ERROR-MESSAGE       PIC X(100).
       
       PROCEDURE DIVISION.
       DEMONSTRATE-ADVANCED-COMPARISONS.
           DISPLAY 'Demonstrating Advanced Comparison Techniques'
           DISPLAY '==========================================='
           
       *> Demonstrate condition name comparisons
           PERFORM DEMONSTRATE-CONDITION-NAMES
           
       *> Demonstrate complex logical expressions
           PERFORM DEMONSTRATE-COMPLEX-LOGICAL-EXPRESSIONS
           
       *> Demonstrate range comparisons
           PERFORM DEMONSTRATE-RANGE-COMPARISONS
           
           STOP RUN.
       
       DEMONSTRATE-CONDITION-NAMES.
           DISPLAY 'Condition Name Comparisons:'
           DISPLAY 'Customer Status: ' CUSTOMER-STATUS
           DISPLAY 'Account Type: ' ACCOUNT-TYPE
           DISPLAY 'Transaction Type: ' TRANSACTION-TYPE
           DISPLAY ' '
           
       *> Test customer status using condition names
           IF ACTIVE-CUSTOMER
               DISPLAY 'Customer is ACTIVE (using condition name)'
           ELSE
               IF INACTIVE-CUSTOMER
                   DISPLAY 'Customer is INACTIVE (using condition name)'
               ELSE
                   IF SUSPENDED-CUSTOMER
                       DISPLAY 'Customer is SUSPENDED (using condition name)'
                   END-IF
               END-IF
           END-IF
           
       *> Test account type using condition names
           IF CHECKING-ACCOUNT
               DISPLAY 'Account is CHECKING (using condition name)'
           ELSE
               IF SAVINGS-ACCOUNT
                   DISPLAY 'Account is SAVINGS (using condition name)'
               ELSE
                   IF BUSINESS-ACCOUNT
                       DISPLAY 'Account is BUSINESS (using condition name)'
                   END-IF
               END-IF
           END-IF
           
       *> Test transaction type using condition names
           IF DEPOSIT-TRANSACTION
               DISPLAY 'Transaction is DEPOSIT (using condition name)'
           ELSE
               IF WITHDRAWAL-TRANSACTION
                   DISPLAY 'Transaction is WITHDRAWAL (using condition name)'
               ELSE
                   IF TRANSFER-TRANSACTION
                       DISPLAY 'Transaction is TRANSFER (using condition name)'
                   END-IF
               END-IF
           END-IF.
       
       DEMONSTRATE-COMPLEX-LOGICAL-EXPRESSIONS.
           DISPLAY 'Complex Logical Expressions:'
           DISPLAY 'Customer Age: ' CUSTOMER-AGE
           DISPLAY 'Customer Income: ' CUSTOMER-INCOME
           DISPLAY 'Customer Credit Score: ' CUSTOMER-CREDIT-SCORE
           DISPLAY ' '
           
       *> Complex condition: Age AND Income requirements
           IF CUSTOMER-AGE >= 18 AND CUSTOMER-AGE <= 65
               IF CUSTOMER-INCOME >= 30000.00
                   DISPLAY 'Customer meets age AND income requirements'
               ELSE
                   DISPLAY 'Customer meets age requirements but not income'
               END-IF
           ELSE
               DISPLAY 'Customer does not meet age requirements'
           END-IF
           
       *> Complex condition: Credit score OR Income requirements
           IF CUSTOMER-CREDIT-SCORE >= 700 OR CUSTOMER-INCOME >= 75000.00
               DISPLAY 'Customer meets credit score OR income requirements'
           ELSE
               DISPLAY 'Customer does not meet credit score OR income requirements'
           END-IF
           
       *> Complex condition: Multiple conditions with NOT
           IF ACTIVE-CUSTOMER AND NOT SUSPENDED-CUSTOMER
               IF CUSTOMER-CREDIT-SCORE > 600
                   DISPLAY 'Customer is active, not suspended, and has good credit'
               ELSE
                   DISPLAY 'Customer is active and not suspended but has poor credit'
               END-IF
           ELSE
               DISPLAY 'Customer is not active or is suspended'
           END-IF.
       
       DEMONSTRATE-RANGE-COMPARISONS.
           DISPLAY 'Range Comparisons:'
           DISPLAY 'Account Balance: ' ACCOUNT-BALANCE
           DISPLAY 'Account Limit: ' ACCOUNT-LIMIT
           DISPLAY 'Transaction Amount: ' TRANSACTION-AMOUNT
           DISPLAY ' '
           
       *> Range comparison: Check if balance is within acceptable range
           IF ACCOUNT-BALANCE >= 0 AND ACCOUNT-BALANCE <= ACCOUNT-LIMIT
               DISPLAY 'Account balance is within acceptable range'
           ELSE
               DISPLAY 'Account balance is outside acceptable range'
           END-IF
           
       *> Range comparison: Check if transaction amount is reasonable
           IF TRANSACTION-AMOUNT > 0 AND TRANSACTION-AMOUNT <= 5000.00
               DISPLAY 'Transaction amount is within reasonable range'
           ELSE
               DISPLAY 'Transaction amount is outside reasonable range'
           END-IF
           
       *> Range comparison: Check if customer qualifies for premium service
           IF CUSTOMER-INCOME >= 100000.00 AND CUSTOMER-CREDIT-SCORE >= 800
               DISPLAY 'Customer qualifies for premium service'
           ELSE
               IF CUSTOMER-INCOME >= 50000.00 AND CUSTOMER-CREDIT-SCORE >= 700
                   DISPLAY 'Customer qualifies for standard service'
               ELSE
                   DISPLAY 'Customer qualifies for basic service'
               END-IF
           END-IF.

This example demonstrates advanced comparison techniques including condition names (88-level items), complex logical expressions with AND and OR operators, and range comparisons. Condition names provide a more readable way to test for specific values, while complex logical expressions allow for sophisticated decision-making based on multiple conditions. Range comparisons are useful for validating data within acceptable limits.

Comparison with Different Data Types

1. Numeric Data Comparisons

Numeric data comparisons in COBOL work with various numeric formats including binary, packed decimal, and display numeric. COBOL automatically handles the conversion between different numeric formats during comparison operations.

cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
       IDENTIFICATION DIVISION.
       PROGRAM-ID. NUMERIC-DATA-COMPARISONS.
       *> This program demonstrates numeric data comparisons
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       *> Different numeric data types for comparison
       01 BINARY-NUMERIC-DATA.
           05 BINARY-NUMBER-1    PIC 9(5) COMP VALUE 1000.
           05 BINARY-NUMBER-2    PIC 9(5) COMP VALUE 2000.
       
       01 PACKED-DECIMAL-DATA.
           05 PACKED-NUMBER-1    PIC 9(5)V99 COMP-3 VALUE 1000.50.
           05 PACKED-NUMBER-2    PIC 9(5)V99 COMP-3 VALUE 2000.75.
       
       01 DISPLAY-NUMERIC-DATA.
           05 DISPLAY-NUMBER-1   PIC 9(5)V99 VALUE 1000.50.
           05 DISPLAY-NUMBER-2   PIC 9(5)V99 VALUE 2000.75.
       
       01 MIXED-NUMERIC-DATA.
           05 INTEGER-VALUE      PIC 9(3) VALUE 100.
           05 DECIMAL-VALUE      PIC 9(3)V99 VALUE 100.00.
           05 FRACTIONAL-VALUE   PIC 9(3)V99 VALUE 100.50.
       
       PROCEDURE DIVISION.
       DEMONSTRATE-NUMERIC-COMPARISONS.
           DISPLAY 'Demonstrating Numeric Data Comparisons'
           DISPLAY '======================================'
           
       *> Compare binary numeric values
           PERFORM COMPARE-BINARY-NUMERIC
           
       *> Compare packed decimal values
           PERFORM COMPARE-PACKED-DECIMAL
           
       *> Compare display numeric values
           PERFORM COMPARE-DISPLAY-NUMERIC
           
       *> Compare mixed numeric types
           PERFORM COMPARE-MIXED-NUMERIC-TYPES
           
           STOP RUN.
       
       COMPARE-BINARY-NUMERIC.
           DISPLAY 'Binary Numeric Comparisons:'
           DISPLAY 'Binary Number 1: ' BINARY-NUMBER-1
           DISPLAY 'Binary Number 2: ' BINARY-NUMBER-2
           DISPLAY ' '
           
           IF BINARY-NUMBER-1 < BINARY-NUMBER-2
               DISPLAY 'Binary: 1000 < 2000 (TRUE)'
           END-IF
           
           IF BINARY-NUMBER-1 = 1000
               DISPLAY 'Binary: 1000 = 1000 (TRUE)'
           END-IF
           
           IF BINARY-NUMBER-2 > BINARY-NUMBER-1
               DISPLAY 'Binary: 2000 > 1000 (TRUE)'
           END-IF.
       
       COMPARE-PACKED-DECIMAL.
           DISPLAY 'Packed Decimal Comparisons:'
           DISPLAY 'Packed Number 1: ' PACKED-NUMBER-1
           DISPLAY 'Packed Number 2: ' PACKED-NUMBER-2
           DISPLAY ' '
           
           IF PACKED-NUMBER-1 < PACKED-NUMBER-2
               DISPLAY 'Packed: 1000.50 < 2000.75 (TRUE)'
           END-IF
           
           IF PACKED-NUMBER-1 = 1000.50
               DISPLAY 'Packed: 1000.50 = 1000.50 (TRUE)'
           END-IF
           
           IF PACKED-NUMBER-2 > PACKED-NUMBER-1
               DISPLAY 'Packed: 2000.75 > 1000.50 (TRUE)'
           END-IF.
       
       COMPARE-DISPLAY-NUMERIC.
           DISPLAY 'Display Numeric Comparisons:'
           DISPLAY 'Display Number 1: ' DISPLAY-NUMBER-1
           DISPLAY 'Display Number 2: ' DISPLAY-NUMBER-2
           DISPLAY ' '
           
           IF DISPLAY-NUMBER-1 < DISPLAY-NUMBER-2
               DISPLAY 'Display: 1000.50 < 2000.75 (TRUE)'
           END-IF
           
           IF DISPLAY-NUMBER-1 = 1000.50
               DISPLAY 'Display: 1000.50 = 1000.50 (TRUE)'
           END-IF
           
           IF DISPLAY-NUMBER-2 > DISPLAY-NUMBER-1
               DISPLAY 'Display: 2000.75 > 1000.50 (TRUE)'
           END-IF.
       
       COMPARE-MIXED-NUMERIC-TYPES.
           DISPLAY 'Mixed Numeric Type Comparisons:'
           DISPLAY 'Integer Value: ' INTEGER-VALUE
           DISPLAY 'Decimal Value: ' DECIMAL-VALUE
           DISPLAY 'Fractional Value: ' FRACTIONAL-VALUE
           DISPLAY ' '
           
       *> Compare integer with decimal (both represent 100)
           IF INTEGER-VALUE = DECIMAL-VALUE
               DISPLAY 'Integer 100 = Decimal 100.00 (TRUE)'
           ELSE
               DISPLAY 'Integer 100 ≠ Decimal 100.00 (FALSE)'
           END-IF
           
       *> Compare integer with fractional
           IF INTEGER-VALUE < FRACTIONAL-VALUE
               DISPLAY 'Integer 100 < Fractional 100.50 (TRUE)'
           ELSE
               DISPLAY 'Integer 100 ≥ Fractional 100.50 (FALSE)'
           END-IF
           
       *> Compare decimal with fractional
           IF DECIMAL-VALUE < FRACTIONAL-VALUE
               DISPLAY 'Decimal 100.00 < Fractional 100.50 (TRUE)'
           ELSE
               DISPLAY 'Decimal 100.00 ≥ Fractional 100.50 (FALSE)'
           END-IF.

This example demonstrates how COBOL handles comparisons between different numeric data types. The program shows comparisons between binary numeric, packed decimal, and display numeric values. COBOL automatically converts between these formats during comparison operations, allowing seamless comparison of different numeric representations. The example also shows how integer and decimal values are compared, including cases where they represent the same numeric value.

2. Character Data Comparisons

Character data comparisons in COBOL are based on the collating sequence, which determines the order of characters. String comparisons are performed character by character from left to right, and the comparison stops when a difference is found or when one string is exhausted.

cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
       IDENTIFICATION DIVISION.
       PROGRAM-ID. CHARACTER-DATA-COMPARISONS.
       *> This program demonstrates character data comparisons
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       *> Character data for comparison demonstrations
       01 STRING-COMPARISON-DATA.
           05 STRING-1           PIC X(10) VALUE 'APPLE'.
           05 STRING-2           PIC X(10) VALUE 'BANANA'.
           05 STRING-3           PIC X(10) VALUE 'APPLE'.
           05 STRING-4           PIC X(10) VALUE 'APPLES'.
           05 STRING-5           PIC X(10) VALUE 'APRICOT'.
       
       01 CASE-SENSITIVE-DATA.
           05 UPPERCASE-STRING   PIC X(10) VALUE 'HELLO'.
           05 LOWERCASE-STRING   PIC X(10) VALUE 'hello'.
           05 MIXED-CASE-STRING  PIC X(10) VALUE 'Hello'.
       
       01 ALPHANUMERIC-DATA.
           05 ALPHA-STRING-1     PIC X(10) VALUE 'ABC123'.
           05 ALPHA-STRING-2     PIC X(10) VALUE 'ABC124'.
           05 ALPHA-STRING-3     PIC X(10) VALUE 'ABD123'.
       
       PROCEDURE DIVISION.
       DEMONSTRATE-CHARACTER-COMPARISONS.
           DISPLAY 'Demonstrating Character Data Comparisons'
           DISPLAY '======================================'
           
       *> Demonstrate basic string comparisons
           PERFORM DEMONSTRATE-BASIC-STRING-COMPARISONS
           
       *> Demonstrate case sensitivity
           PERFORM DEMONSTRATE-CASE-SENSITIVITY
           
       *> Demonstrate alphanumeric comparisons
           PERFORM DEMONSTRATE-ALPHANUMERIC-COMPARISONS
           
           STOP RUN.
       
       DEMONSTRATE-BASIC-STRING-COMPARISONS.
           DISPLAY 'Basic String Comparisons:'
           DISPLAY 'String 1: ' STRING-1
           DISPLAY 'String 2: ' STRING-2
           DISPLAY 'String 3: ' STRING-3
           DISPLAY 'String 4: ' STRING-4
           DISPLAY 'String 5: ' STRING-5
           DISPLAY ' '
           
       *> Equal comparison
           IF STRING-1 = STRING-3
               DISPLAY 'APPLE = APPLE (TRUE) - Exact match'
           ELSE
               DISPLAY 'APPLE ≠ APPLE (FALSE) - No match'
           END-IF
           
       *> Not equal comparison
           IF STRING-1 NOT = STRING-2
               DISPLAY 'APPLE ≠ BANANA (TRUE) - Different strings'
           ELSE
               DISPLAY 'APPLE = BANANA (FALSE) - Same strings'
           END-IF
           
       *> Less than comparison (alphabetical order)
           IF STRING-1 < STRING-2
               DISPLAY 'APPLE < BANANA (TRUE) - A comes before B'
           ELSE
               DISPLAY 'APPLE ≥ BANANA (FALSE) - A does not come before B'
           END-IF
           
       *> Greater than comparison
           IF STRING-2 > STRING-1
               DISPLAY 'BANANA > APPLE (TRUE) - B comes after A'
           ELSE
               DISPLAY 'BANANA ≤ APPLE (FALSE) - B does not come after A'
           END-IF
           
       *> Comparison with different lengths
           IF STRING-1 < STRING-4
               DISPLAY 'APPLE < APPLES (TRUE) - Shorter string comes first'
           ELSE
               DISPLAY 'APPLE ≥ APPLES (FALSE) - Shorter string does not come first'
           END-IF.
       
       DEMONSTRATE-CASE-SENSITIVITY.
           DISPLAY 'Case Sensitivity Comparisons:'
           DISPLAY 'Uppercase: ' UPPERCASE-STRING
           DISPLAY 'Lowercase: ' LOWERCASE-STRING
           DISPLAY 'Mixed Case: ' MIXED-CASE-STRING
           DISPLAY ' '
           
       *> Case-sensitive comparisons
           IF UPPERCASE-STRING = LOWERCASE-STRING
               DISPLAY 'HELLO = hello (TRUE) - Case insensitive'
           ELSE
               DISPLAY 'HELLO ≠ hello (FALSE) - Case sensitive'
           END-IF
           
           IF UPPERCASE-STRING = MIXED-CASE-STRING
               DISPLAY 'HELLO = Hello (TRUE) - Case insensitive'
           ELSE
               DISPLAY 'HELLO ≠ Hello (FALSE) - Case sensitive'
           END-IF
           
           IF LOWERCASE-STRING = MIXED-CASE-STRING
               DISPLAY 'hello = Hello (TRUE) - Case insensitive'
           ELSE
               DISPLAY 'hello ≠ Hello (FALSE) - Case sensitive'
           END-IF.
       
       DEMONSTRATE-ALPHANUMERIC-COMPARISONS.
           DISPLAY 'Alphanumeric Comparisons:'
           DISPLAY 'Alpha String 1: ' ALPHA-STRING-1
           DISPLAY 'Alpha String 2: ' ALPHA-STRING-2
           DISPLAY 'Alpha String 3: ' ALPHA-STRING-3
           DISPLAY ' '
           
       *> Compare alphanumeric strings
           IF ALPHA-STRING-1 < ALPHA-STRING-2
               DISPLAY 'ABC123 < ABC124 (TRUE) - Numbers compared'
           ELSE
               DISPLAY 'ABC123 ≥ ABC124 (FALSE) - Numbers not compared correctly'
           END-IF
           
           IF ALPHA-STRING-1 < ALPHA-STRING-3
               DISPLAY 'ABC123 < ABD123 (TRUE) - Letters compared'
           ELSE
               DISPLAY 'ABC123 ≥ ABD123 (FALSE) - Letters not compared correctly'
           END-IF
           
           IF ALPHA-STRING-2 < ALPHA-STRING-3
               DISPLAY 'ABC124 < ABD123 (TRUE) - Mixed comparison'
           ELSE
               DISPLAY 'ABC124 ≥ ABD123 (FALSE) - Mixed comparison'
           END-IF.

This example demonstrates character data comparisons in COBOL, showing how strings are compared character by character based on the collating sequence. The program illustrates basic string comparisons, case sensitivity (which depends on the system's collating sequence), and alphanumeric comparisons. String comparisons stop at the first difference found, and shorter strings are considered "less than" longer strings when they are otherwise identical.

Best Practices for Comparison Operations

Common Comparison Patterns

Conditional Logic

Learn conditional logic techniques

Data Validation

Master data validation methods

Collating Sequence

Learn character ordering

Condition Names

Master condition names

Logical Operations

Learn logical operations

Data Types

Understand data types