param

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Revision as of 21:21, 12 October 2015 by Killzone Kid (talk | contribs) (on screen errors)
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Description

Description:
Extracts a single value with given index from input argument, similar to BIS_fnc_param. When used without argument, as shown in main syntax, internal variable _this, which is usually available inside functions and event handlers, is used as argument. If input argument is not an array, it will be converted to 1 element array.

If extracted item of input with given index is undefined, of the wrong type or of the wrong length (if the item is an array), default value is used instead. Since Arma 3 v1.53.132691, onscreen errors are displayed for when the input is of the wrong type or size.
Groups:
Uncategorised

Syntax

Syntax:
param [index, defaultValue, expectedDataTypes, expectedArrayCount]
Parameters:
[index, defaultValue, expectedDataTypes, expectedArrayCount]: Array
index: Number - index of required item in the input array.
defaultValue (Optional): Anything - a default value to return if input is undefined, of the wrong type or of the wrong length (if the item is an array).
expectedDataTypes (Optional): Array of direct Data Types - checks if passed value is one of listed Data Types. If not, default value is used instead. Empty array [] means every data type is accepted.
expectedArrayCount (Optional): Number or Array - a single size or array of sizes. If passed input value is an array, checks that it has a certain number of elements. If not, default value is used instead. Empty array [] means any size is accepted.
Return Value:
Anything - extracted value on success or default value otherwise. Nothing if syntax error occurred.

Alternative Syntax

Syntax:
argument param [index, defaultValue, expectedDataTypes, expectedArrayCount]
Parameters:
argument: Anything - A usual array of params is expected. If a non-array value is passed, it will be converted to 1 element array
[index, defaultValue, expectedDataTypes, expectedArrayCount]: Array
index: Number - index of required item in the input array.
defaultValue (Optional): Anything - a default value to return if input is undefined, of the wrong type or of the wrong length (if the item is an array).
expectedDataTypes (Optional): Array of direct Data Types - checks if passed value is one of listed Data Types. If not, default value is used instead. Empty array [] means every data type is accepted.
expectedArrayCount (Optional): Number or Array - a single size or array of sizes. If passed input value is an array, checks that it has a certain number of elements. If not, default value is used instead. Empty array [] means any size is accepted.
Return Value:
Anything - extracted value on success or default value otherwise. Nothing if syntax error occurred.

Examples

Example 1:
[1, 2, 3] call { private ["_one", "_two", "_three"]; _one = param [0, 1]; _two = param [1, 2]; _three = param [2, 3]; // ..... };
Example 2:
[123] call { private "_val"; _val = param [0]; }; // Below would produce the same result as above 123 call { private "_val"; _val = param [0]; };
Example 3:
_z = position player param [2, 0]; if (_z > 10) then { hint "YOU ARE FLYING!"; };
Example 4:
fnc = { private ["_pos", "_rad"] _pos = param [0, [0,0,0], [objNull, []], [2,3]]; _rad = param [1, 0, [0]]; _pos nearObjects _rad; }; [position player, 25] call fnc; //ok [player, 25] call fnc; //ok [25, player] call fnc; //default values are used

Additional Information

See also:
paramsselectsetresizereverseinfindtoArraytoStringforEachcountdeleteAtdeleteRangeappendsortarrayIntersectsplitStringjoinStringBIS_fnc_param

Notes

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