isNil

1.00

Hover & click on the images for descriptions

Description

Description:

Tests whether the variable given by its name is nil or undefined, or whether the given expression evaluates to nil or Nothing.

ⓘ

1.00 This command doesn't exist in Operation Flashpoint but can be emulated (see Example 5).

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

Groups:

Variables

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