View source for ORELSE

{{DISPLAYTITLE:_ORELSE}}
[[_ORELSE]] is a [[Boolean|boolean]] logical operator that performs short-circuiting inclusive logical disjunction on two expressions.


{{PageSyntax}}
:{{Parameter|result}} = {{Parameter|firstvalue}} [[_ORELSE]] {{Parameter|secondvalue}}


{{PageDescription}}
* 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.


{{PageAvailability}}
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{{PageExamples}}
''Example:'' OR versus _ORELSE
{{CodeStart}}
{{Cl|PRINT}} {{Text|<nowiki>"Trying _ORELSE"</nowiki>|#FFB100}}

{{Text|<nowiki>' _ORELSE performs short-circuiting logical conjunction and hence for "strawberry", only isFruit() is called</nowiki>|#919191}}
{{Cl|IF}} {{Text|isFruit|#55FF55}}({{Text|<nowiki>"strawberry"</nowiki>|#FFB100}}) {{Cl|_ORELSE}} {{Text|isRed|#55FF55}}({{Text|<nowiki>"strawberry"</nowiki>|#FFB100}}) {{Cl|_ORELSE}} {{Text|isSeasonal|#55FF55}}({{Text|<nowiki>"strawberry"</nowiki>|#FFB100}}) {{Cl|THEN}}
    {{Cl|PRINT}} {{Text|<nowiki>"Probably a strawberry."</nowiki>|#FFB100}}
{{Cl|ELSE}}
    {{Cl|PRINT}} {{Text|<nowiki>"Certainly not a strawberry."</nowiki>|#FFB100}}
{{Cl|END IF}}

{{Cl|PRINT}}
{{Cl|PRINT}} {{Text|<nowiki>"Trying OR"</nowiki>|#FFB100}}

{{Text|<nowiki>' OR does not performs short-circuiting logical conjunction and hence all is***() functions are called</nowiki>|#919191}}
{{Cl|IF}} {{Text|isFruit|#55FF55}}({{Text|<nowiki>"strawberry"</nowiki>|#FFB100}}) {{Cl|OR (boolean)|OR}} {{Text|isRed|#55FF55}}({{Text|<nowiki>"strawberry"</nowiki>|#FFB100}}) {{Cl|OR (boolean)|OR}} {{Text|isSeasonal|#55FF55}}({{Text|<nowiki>"strawberry"</nowiki>|#FFB100}}) {{Cl|THEN}}
    {{Cl|PRINT}} {{Text|<nowiki>"Probably a strawberry."</nowiki>|#FFB100}}
{{Cl|ELSE}}
    {{Cl|PRINT}} {{Text|<nowiki>"Certainly not a strawberry."</nowiki>|#FFB100}}
{{Cl|END IF}}

{{Cl|END}}

{{Cl|FUNCTION}} {{Text|isFruit%%|#55FF55}} (fruit {{Cl|AS}} {{Cl|STRING}})
    {{Cl|PRINT}} {{Text|<nowiki>"isFruit() called!"</nowiki>|#FFB100}}
    {{Text|isFruit|#55FF55}} = (fruit = {{Text|<nowiki>"strawberry"</nowiki>|#FFB100}})
{{Cl|END FUNCTION}}

{{Cl|FUNCTION}} {{Text|isRed%%|#55FF55}} (fruit {{Cl|AS}} {{Cl|STRING}})
    {{Cl|PRINT}} {{Text|<nowiki>"isRed() called!"</nowiki>|#FFB100}}
    {{Text|isRed|#55FF55}} = (fruit = {{Text|<nowiki>"strawberry"</nowiki>|#FFB100}})
{{Cl|END FUNCTION}}

{{Cl|FUNCTION}} {{Text|isSeasonal%%|#55FF55}} (fruit {{Cl|AS}} {{Cl|STRING}})
    {{Cl|PRINT}} {{Text|<nowiki>"isSeasonal() called!"</nowiki>|#FFB100}}
    {{Text|isSeasonal|#55FF55}} = (fruit = {{Text|<nowiki>"strawberry"</nowiki>|#FFB100}})
{{Cl|END FUNCTION}}
{{CodeEnd}}
{{OutputStart}}Trying _ORELSE
isFruit() called!
Probably a strawberry.

Trying OR
isFruit() called!
isRed() called!
isSeasonal() called!
Probably a strawberry.
{{OutputEnd}}

{{PageSeeAlso}}
* [https://qb64phoenix.com/forum/showthread.php?tid=2661 Featured in our "Keyword of the Day" series]
* [[_BIT]], [[&B]], [[_BYTE]]
* [[AND]], [[XOR]], [[OR]]
* [[AND (boolean)]], [[XOR (boolean)]], [[OR (boolean)]]
* [[_ANDALSO]], [[_NEGATE]]
* [[Binary]], [[Boolean]]
* [[Mathematical Operations]]


{{PageNavigation}}