isNil: Difference between revisions
Lou Montana (talk | contribs) m (Text replacement - "\{\{( *)Informative( *)\|" to "{{$1Feature$2|$2Informative$2|")  | 
				Lou Montana (talk | contribs)  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
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).
 
 - the code will be executed; 
 - 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
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