isNil

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Description

Description:
Tests whether the variable given by its name is nil or undefined, or whether the given expression evaluates to nil or Nothing.
Logo A0.png1.00 This command doesn't exist in Operation Flashpoint but can be emulated (see Example 5).
Groups:
Variables

Syntax

Syntax:
isNil variableName
Parameters:
variableName: String - name of a missionNamespace variable (e.g "someVar") or a local variable (e.g "_someVar")
Return Value:
Boolean - true if variable is nil

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

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