COBOL Manual for TNS/E Programs (H06.03+)

Procedure Division
HP COBOL Manual for TNS/E Programs—520347-003
8-63
Simple Conditions
Sign Conditions
The sign condition determines whether the algebraic value of an arithmetic expression
is less than, greater than, or equal to zero.
arithmetic-expression
is an arithmetic expression, as described in Arithmetic Expressions
.
Usage Considerations:
•
NOT Modifier
When NOT appears, it and the next keyword are considered to form a single sign
condition. For example, NOT ZERO is a truth test that determines if the operand
value is nonzero (is positive or negative).
•
Definition
An operand is positive if its value is greater than zero, negative if its value is less
than zero, and zero if its value is equal to zero.
Example 8-13. External Switches
SPECIAL-NAMES.
SWITCH-1 IS IN-SWITCH ON STATUS IS TAPE-INPUT
OFF STATUS IS DISK-INPUT
SWITCH-2 IS OUT-SWITCH ON STATUS IS TAPE-OUTPUT
OFF STATUS IS DISK-OUTPUT.
...
PROCEDURE DIVISION.
...
IF TAPE-INPUT OPEN INPUT TAPE-SOURCE
ELSE OPEN INPUT DISK-SOURCE.
IF TAPE-OUTPUT OPEN OUTPUT TAPE-SINK
ELSE OPEN OUTPUT DISK-SINK.
...
arithmetic-expression
POSITIVE
NEGATIVE
ZERO
IS NOT
VST121.vsd