isNil: Difference between revisions

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m (Text replacement - "\{\{( *)Informative( *)\|" to "{{$1Feature$2|$2Informative$2|")
m (Text replacement - "\| *((\[\[[a-zA-Z0-9_ |()]+\]\],? ?)+) * \}\}" to "|seealso= $1 }}")
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[[if]] ([[format]] ["%1", foo] == _nil) [[then]] { foo = "value"; };</code>
[[if]] ([[format]] ["%1", foo] == _nil) [[then]] { foo = "value"; };</code>


| [[nil]], [[Variables]], [[Scheduler]]
|seealso= [[nil]], [[Variables]], [[Scheduler]]
}}
}}



Revision as of 23:48, 16 February 2021

Hover & click on the images for description

Description

Description:
Description needed
Groups:
Variables

Syntax

Syntax:
Syntax needed
Parameters:
variableName: String - name of a missionNamespace variable (e.g "someVar") or a local variable (e.g "_someVar")
Return Value:
Return value needed

Alternative Syntax

Syntax:
isNil code
Parameters:
code: Code - code to evaluate:
  • the code will be executed; isNil { player setDamage 1; }; will kill the player
  • the code will not be allowed to suspend while expression is evaluated, even if the parent scope allows it (see Example 4).
Return Value:
Boolean - true if code returns something other than Nothing

Examples

Example 1:
if (isNil "pokus") then { pokus = 0; };
Example 2:
isNil { player getVariable "someVar" };
Example 3:
_myArray = [0, 1]; isNil { _myArray select 0 }; // returns false isNil { _myArray select 1 }; // returns false isNil { _myArray select 2 }; // returns true isNil { _myArray select 3 }; // throws a script error. only length+1 select is allowed
Example 4:
You can do this trick to force execute something in Unscheduled Environment.spawn { systemChat str canSuspend; // chat shows true isNil {hint str canSuspend}; // hint shows false };
Example 5:
Operation Flashpoint workaround:
SQS syntax: _nil = format ["%1", _undefinedVariable] ? (format ["%1", foo] == _nil) : foo = "value" SQF syntax: _nil = format ["%1", _undefinedVariable]; if (format ["%1", foo] == _nil) then { foo = "value"; };

Additional Information

See also:
nilVariablesScheduler

Notes

Report bugs on the Feedback Tracker and/or discuss them on the Arma Discord or on the Forums.
Only post proven facts here! Add Note