ARTICLE
log_exp - Boolean Operators and Parentheses
The Boolean operators
AND
OR
EQUIV
join logical expressions; the operator
NOT
negates a logical expression.
Logical expressions can be parenthesized explicitly using
( )
.
When combining multiple Boolean operators, the system implicitly
parenthesizes all logical expressions that are not closed by explicit
parentheses according to the following hierarchy (operator order,
precedence). This expresses the strength of the connection between
Boolean operators:
All Boolean operators NOT are combined with the adjacent logical
expression to the right to a logical expression.
All logical expressions joined using AND are combined as one
logical expression.
All logical expressions joined using OR are combined as one
logical expression.
All logical expressions joined using EQUIV are combined as one
logical expression.
The logical expressions of a parenthesis level are processed from the
left to the right. If the value of a logical expression determines the
total value of the parenthesis level, the remaining logical expressions
are not evaluated. The dynamic parts of the expressions that are not
evaluated, such as field symbols or reference variables, are not checked
for validity in this case.
Notes
If multiple logical expressions are joined, the explicit and implicit
parentheses always produce exactly one logical expression that is either
true or false.
The smallest unit of a joined logical expression is always a
relational expression .
If functional methods are used as
operands in the relational expressions in question, they are executed
directly before the respective relational expression is evaluated. Any
functional methods in a relational expression that does not need to be
evaluated to get the result are not executed.
Documentation extract taken from SAP system, � Copyright SAP AG. All rights reserved