COBOL Condition Names

The name associated with 88-level numbers is Condition Name, and the variables with 88-level numbers are Conditional Variable.

• A condition name is a meaningful name for a value or a range of values of a variable.
• The IF and EVALUATE statements validate whether the condition variable's value is equal to any values associated with the condition name.
• This feature makes the code more readable by allowing programmers to use descriptive names instead of conditional expressions.
• The condition name is declared with 88 level numbers and can code with IF and EVALUATE.

Syntax -

88 condition-name    VALUE value1 [THRU value2].

Where:

• condition-name is the descriptive name of the condition.

Points to Note -

• Condition name is always associated with a variable.
• It doesn't occupy any storage.
• It can code in either in Area-A or Area-B.

Rules to Remember -

• No PICTURE clause is associated with the condition name.
• VALUE clause is mandatory for the condition name.
• Condition name can code with both group and elementary levels.
• Condition name should be subscripted or indexed if the condition variable uses subscripts or indexes.

How can the condition variables be initialized?

Condition variables can be initialized in two ways -

• During their declaration.
• Using SET statement.

During their declaration -

Condition variables are initialized by coding a VALUE clause during its declaration. For example - declaration below initializes the WS-GENDER with 'M', which sets the MALE condition name to true.

 01 WS-GENDER       PIC X(01) VALUE 'M'.
   88 MALE         VALUE 'M'.
   88 FEMALE       VALUE 'F'.

Using SET statement -

We can initialize condition variables by setting condition name (SET statement) to TRUE. For example - The below declaration sets the WS-GENDER value to 'M'.

SET MALE    TO TRUE.

How do we validate the condition name?

IF and EVALUATE statements use condition names to validate conditions as TRUE or FALSE. The program flow is decided based on the truth value.

For example - The below code executes statement-set1 when the WS-GENDER value is 'M'. Otherwise, run statement-set2.

01 WS-GENDER       PIC X(01).
   88 MALE         VALUE 'M'.
   88 FEMALE       VALUE 'F'.
...
IF MALE
	statement-set1
ELSE
	statement-set2
END-IF.

Different Formats -

Condition name has the advantage of being used in three different formats, which are very useful in validating the data.

Format1 - Single Value

The condition name is declared with only one value to validate. Syntax -

 88 Condition-Name VALUE single-value.

For example - MALE & FEMALE condition names have single value.

 01 WS-GENDER       PIC X(01).
   88 MALE         VALUE 'M'.
   88 FEMALE       VALUE 'F'.

With the above definition, we can write -

 IF MALE ...

Instead of -

 IF WS-GENDER EQUAL 'M' ...

Format2 - Multiple values

The condition name is declared to have more than one value to validate. i.e., In a single condition, it can validate with more than one value. Syntax -

 88 Condition-Name VALUE value1 value2...valueN.

For example - VALID-GENDER condition name has the multiple values.

 01 WS-GENDER       PIC X(01).
   88 VALID-GENDER    VALUE 'M' 'F'.
   88 MALE            VALUE 'M'.
   88 FEMALE          VALUE 'F'.

With the above definition, we can write -

 IF VALID-GENDER ...

Instead of -

 IF WS-GENDER EQUAL 'M' 
 OR WS-GENDER EQUAL 'Y' ...

Format3 - Range of values

Condition name is declared with a range of values to validate. i.e., In a single condition, it can validate with a range of values started from one value to another in a sequence. Syntax -

88 Condition-Name VALUE value1 THRU literalN.

For example - FIRST-CLASS, SECOND-CALSS, THIRD-CLASS & FAIL condition name has a range of values.

 01 WS-MARKS       PIC 9(03).
   88 FIRST-CLASS     VALUE 60 THROUGH 100.
   88 SECOND-CLASS    VALUE 50 THROUGH 59.
   88 THIRD-CLASS     VALUE 35 THROUGH 49.
   88 FAIL            VALUE 00 THROUGH 34.

With the above definition, we can write -

 IF FIRST-CLASS ...

Instead of -

 IF  WS-MARKS <= 100
 AND WS-MARKS >= 60 ...

Practical Example -

Scenario - Declaring condition names (all formats) and their usage in PROCEDURE DIVISION.

Code -

----+----1----+----2----+----3----+----4----+----5----+
       ...  
       WORKING-STORAGE SECTION.

       01 WS-ALPHABET       PIC X(01).
	  * Condition names with single values
          88 ALPHABET-A     VALUE "A". 
          88 ALPHABET-S     VALUE "S".
      * Condition names with multiple values
          88 VALID-ALPHABET VALUE "A" THROUGH "Z". 
          88 VOWELS         VALUE "A" "E" "I" "O" "U".
      * Condition names with range of values		  
          88 CONSONANTS     VALUE "B" THRU "D" 
                                  "F" THRU "H"
                                  "J" THRU "N"
                                  "P" THRU "T"
                                  "V" THRU "Z". 
       ...
       PROCEDURE DIVISION. 

           SET ALPHABET-A    TO TRUE.
           IF  VOWELS
               DISPLAY "ALPHABET IS VOWEL"
           END-IF.

           SET ALPHABET-S    TO TRUE. 
           IF  CONSONANTS
               DISPLAY  "ALPHABET IS CONSONENTS" 
           END-IF. 
		   ...

Output -

Explaining Example -

In the above example:

• WS-ALPHABET is declared as a single-byte alphanumeric variable. It has five condition names.
• ALPHABET-A and ALPHABET-S are single-value condition names. VOWELS is a multiple-value condition name. VALID-ALPHABET CONSONANTS is a condition name with a set of values.