params

1.48

Hover & click on the images for description

Description

Description:

Parses input argument into array of private variables, 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.

In addition to simple parsing directly into variables, input can be tested in case it is undefined, of the wrong type or of the wrong size (if array) and substituted if necessary with default values. Substitutes can also be logged into .rpt file, if allowFunctionsLog param in description.ext is set to 1.

Groups:

Uncategorised

Syntax

Syntax:

params [element1, element2,...elementN]

Parameters:

[element1, element2,...elementN]: Array - format array

elementN: String or Array
If String then it is the name of a private variable (must begin with underscore _, e.g. "_myVar")
If Array then it should be one of the following constructs:

• [variableName, defaultValue]
• [variableName, defaultValue, expectedDataTypes]
• [variableName, defaultValue, expectedDataTypes, expectedArrayCount]

variableName: String - name of a private variable (must begin with underscore _, e.g. "_myVar")

defaultValue: Anything - default value to return if input element is undefined, of the wrong type or of the wrong size (if 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:

Boolean - false if error occurred or default value has been used, otherwise true

Alternative Syntax

Syntax:

argument params [element1, element2,...elementN]

Parameters:

argument: Anything - A usual array of params is expected. If a non-array argument is passed, it will be converted to 1 element array

[element1, element2,...elementN]: Array - format array

elementN: String or Array:
If String then it is the name of a private variable (must begin with underscore _, e.g. "_myVar")
If Array then it should be one of the following constructs:

• [variableName, defaultValue]
• [variableName, defaultValue, expectedDataTypes]
• [variableName, defaultValue, expectedDataTypes, expectedArrayCount]

variableName: String - name of a private variable (must begin with underscore _, e.g. "_myVar")

defaultValue: Anything - default value to return if input element is undefined, of the wrong type or of the wrong size (if 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:

Boolean - false if error occurred or default value has been used, otherwise true

Examples

Example 1:

[1, 2, 3] call { private ["_one", "_two", "_three"]; _one = _this select 0; _two = _this select 1; _three = _this select 2; // ..... }; // Same as above, only using params [1, 2, 3] call { params ["_one", "_two", "_three"]; // ..... };

Example 2:

[123] call { params ["_myvar"]; }; // Below would produce the same result as above 123 call { params ["_myvar"]; };

Example 3:

position player params ["", "", "_z"]; if (_z > 10) then { hint "YOU ARE FLYING!"; };

Example 4:

[1, nil, 2] params ["_var1", "_var2", "_var3"]; // All 3 variables are made private but only _var1 and _var3 are defined [1, nil, 2] params ["_var1", ["_var2", 23], "_var3"]; // All 3 variables are private and defined

Example 5:

[1, 2] call { if (!params ["_var1", "_var2", ["_var3", true, [true]]) exitWith {}; hint str [_var1, _var2, _var3]; }; // The hint shows [1,2,true] [1, 2, 3] call { if (!params ["_var1", "_var2", ["_var3", true, [true]]) exitWith {}; hint str [_var1, _var2, _var3]; }; // Error! Type Number, expected BOOL

Example 6:

[1, "ok", [1, 2, 3]] call { if (!params [ ["_var1", 0, [0]], ["_var2", "", [""]], ["_var3", [0,0,0], [[], objNull, 0], [2,3]] ]) exitWith {}; hint "ok"; }; // Passes validation [1, 2, [3, 4, 5]] call { if (!params ["_var1", "_var2", ["_var3", [], [[], objNull, 0], 0]]) exitWith {}; hint "ok"; }; // Fails, because passed array is expected to be of 0 length, i.e. empty

Example 7:

position player params ["_x", "_y"]; player setPos [_x, _y, 100];

Example 8:

[1, 2, 3, [4, 5, 6]] call { params ["_one", "_two", "_three"]; _this select 3 params ["_four", "_five", "_six"]; };

Example 9:

{ _x params ["_group", "_index"]; // ..... } forEach waypoints group player; fn_someFnc = { params ["_position", ["_direction", 0], ["_name", ""]]; // Extract the x, y, and z from "_position" array: _position params ["_x", "_y", "_z"]; // ..... }; [position player, direction player, name player] call fn_someFnc;

Example 10:

targ addEventHandler ["HitPart", { _this select 0 params ["_target", "_shooter", "_projectile"]; }];

Additional Information

See also:

paramselectsetresizereverseinfindtoArraytoStringforEachcountdeleteAtdeleteRangeappendsortarrayIntersectsplitStringjoinStringBIS_fnc_param

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

Posted on August 30, 2015 - 21:59 (UTC)

Killzone Kid

Because params doubles as private, instead of: [1, 2, 3] params ["_one", "_two", "_three"]; private "_four"; _four = 4; You can just: [1, 2, 3] params ["_one", "_two", "_three", "_four"]; _four = 4;