_ORELSE
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_ORELSE is a boolean logical operator that performs short-circuiting inclusive logical disjunction on two expressions.
Syntax
- result = firstvalue _ORELSE secondvalue
Description
- A logical operation is said to be short-circuiting if the compiled code can bypass the evaluation of one expression depending on the result of another expression.
- If the result of the first expression evaluated determines the final result of the operation, there is no need to evaluate the second expression, because it cannot change the final result.
- Short-circuiting can improve performance if the bypassed expression is complex, or if it involves procedure calls.
- If either or both expressions evaluate to true, result is true.
Availability
Examples
Example: OR versus _ORELSE
PRINT "Trying _ORELSE" ' _ORELSE performs short-circuiting logical conjunction and hence for "strawberry", only isFruit() is called IF isFruit("strawberry") _ORELSE isRed("strawberry") _ORELSE isSeasonal("strawberry") THEN PRINT "Probably a strawberry." ELSE PRINT "Certainly not a strawberry." END IF PRINT PRINT "Trying OR" ' OR does not performs short-circuiting logical conjunction and hence all is***() functions are called IF isFruit("strawberry") OR isRed("strawberry") OR isSeasonal("strawberry") THEN PRINT "Probably a strawberry." ELSE PRINT "Certainly not a strawberry." END IF END FUNCTION isFruit%% (fruit AS STRING) PRINT "isFruit() called!" isFruit = (fruit = "strawberry") END FUNCTION FUNCTION isRed%% (fruit AS STRING) PRINT "isRed() called!" isRed = (fruit = "strawberry") END FUNCTION FUNCTION isSeasonal%% (fruit AS STRING) PRINT "isSeasonal() called!" isSeasonal = (fruit = "strawberry") END FUNCTION |
Trying _ORELSE isFruit() called! Probably a strawberry. Trying OR isFruit() called! isRed() called! isSeasonal() called! Probably a strawberry. |
See also
- _BIT, &B, _BYTE
- AND, XOR, OR
- AND (boolean), XOR (boolean), OR (boolean)
- _ANDALSO, _NEGATE
- Binary, Boolean
- Mathematical Operations