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EVALUATE

Perform logic by cases, such as a decision table.
Restriction: This topic applies only when the AppMaster Builder AddPack has been installed, and applies only to Windows platforms.

Syntax: for Format 1

Standard evaluation procedure

EVALUATE identifier
WHEN valuexpression1
    statementblock
[          .
           .
           .
WHEN valuexpressionN
    statementblockN    ]
[WHEN OTHER
    statementblock     ]

Syntax: for Format 2

Decision table.

EVALUATE identifier1[, ..., identifierN]
WHEN valuexpression1[, ..., valuexpressionN]
    statementblock
[          .
           .
           .
WHEN valuexpressionN+1[, ..., valuexpressionN+N]
    statementblock     ]
[WHEN OTHER
    statementblock     ]

General Rules:

  1. For run time efficiency, AMB generates the GO TO ... DEPENDING ON translation with Format 1, if the code meets the following criteria.
    • Each WHEN valuexpression is a numeric literal.
    • The literals increase in value from left to right, top to bottom.
    • The largest (last) literal in the statement is less than four times as big as the number of WHEN clauses, not counting WHEN OTHER.
  2. If the above criteria are met and the evaluated field is not defined as numeric, a COBOL error occurs.
  3. Only the first WHEN condition met is executed.
  4. If a WHEN condition is true and it does not include an optional statement block, program control passes to the next statement with the same or less indentation as the word EVALUATE.
  5. To prevent logic from falling through if no WHEN conditions are met, code WHEN OTHER.
  6. EVALUATE does not evaluate 88-levels, as the COBOL II EVALUATE statement does.
  7. If a COBOL II EVALUATE statement is also valid S-COBOL EVALUATE syntax, AMB processes it as S-COBOL statement.
  8. You can evaluate a maximum of 255 conditions/fields. You can code a maximum of 102 WHEN conditions.
  9. You can use EVALUATE to code the NEXT SENTENCE concept of passing program control out of a particular construct to the next executable statement.

Parameters:

identifier

Any COBOL identifier

value-xpression

In Format 1, a data name or a group of COBOL literals, identifiers, and arithmetic expressions forming expression1, expression2, . . ..

 

In Format 2, one of the following

ANY, or

expression1 [THRU expression2]... OR expression3[THRU expression4]... [OR expression5 [THRU expression6]]

Symbols such as =, <, and > are not valid.

Example:

Create a mailing list that includes new subscribers (less than 1 year) and preferred subscribers (more than 5 years) broken down by region.
EVALUATE MONTHS, REGION
WHEN 1 THRU 11, 'EAST'
    WRITE NEW-EAST-REC
WHEN 1 THRU 11, 'WEST'
    WRITE NEW-WEST-REC
WHEN 61 THRU 9999, 'EAST'
    WRITE PREFERRED-EAST-REC
WHEN 61 THRU 9999, 'WEST'
    WRITE PREFERRED-WEST-REC
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