EVALUATE command (COBOL)

The EVALUATE command provides a shorthand notation for a series of nested IF statements. The keywords cannot be abbreviated.

any_clause

constant: A valid z/OS® Debugger COBOL constant.
expression: A valid z/OS Debugger COBOL arithmetic expression.
reference: A valid z/OS Debugger COBOL reference.
condition: A simple relation condition.
command: A valid z/OS Debugger command.

Usage notes

Only a single subject is supported.
Consecutive WHENs without associated commands are not supported.
THROUGH⁄THRU ranges can be specified as constants or references.
See Enterprise COBOL for z/OS Language Reference for an explanation of the following COBOL keywords:
- ANY
- FALSE
- NOT
- OTHER
- THROUGH
- THRU
- TRUE
- WHEN
z/OS Debugger implements the EVALUATE command as a series of IF commands.
If the DATA option of the PLAYBACK ENABLE command is in effect for the current compile unit, the EVALUATE command can be used while you replay recorded statements by using the PLAYBACK commands.
For optimized COBOL programs, the value of reference cannot refer to any variables discarded by the optimizer.
If a COBOL variable is defined as National and it is an operand in a relation condition with an alphabetic, alphanumeric operand, or National numeric, the operand that is not National is converted to Unicode before that comparison is done, except for Group items. See Enterprise COBOL for z/OS Language Reference for more information about using COBOL variables in conditional expressions.

Example

The following example shows an EVALUATE command and the equivalent coding for an IF command:

EVALUATE menu-input
  WHEN "0"
    CALL init-proc
  WHEN "1" THRU "9"
    CALL process-proc
  WHEN "R"
    CALL read-parms
  WHEN "X"
    CALL cleanup-proc
  WHEN OTHER
    CALL error-proc
END-EVALUATE;

The equivalent IF command:

IF (menu-input = "0") THEN
  CALL init-proc
ELSE
  IF (menu-input >= "1") AND (menu-input <= "9") THEN
    CALL process-proc
  ELSE
    IF (menu-input = "R") THEN
      CALL read-parms
    ELSE
      IF (menu-input = "X") THEN
        CALL cleanup-proc
      ELSE
        CALL error-proc
      END-IF;
    END-IF;
  END-IF;
END-IF;

Refer to the following topics for more information related to the material discussed in this topic.

Related references
Allowable comparisons for the IF command (COBOL)
Enterprise COBOL for z/OS Language Reference