select

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Description

Description:
Selects an element from an array, config entry from Config or substring from a string or a range from an array.
Groups:
ArraysStringsConfig

Syntax 1

Syntax:
array select index
Parameters:
array: Array
index: Number - index 0 denotes the first element, 1 the second, etc. If index has decimal places it gets rounded down for fractions less than or equal .5, otherwise it gets rounded up.
Arma 3 logo black.png2.12 negative index can be used to select from the end of the array, i.e. -1 means last array element.
Return Value:
Anything - a reference to the array element given by its index
When the index equals the size of the array, there is no error for out of range selection and nil is returned.

Syntax 2

Syntax:
array select boolean
Parameters:
array: Array
boolean: Boolean - false selects the first element of the Array, true the second one
Return Value:
Anything - a reference to the array element

Syntax 3

Syntax:
config select index
Parameters:
config: Config
index: Number - index 0 denotes the first element, 1 the second, etc. If index has decimal places it gets rounded down for fractions less than or equal .5, otherwise it gets rounded up
Return Value:
Config

Syntax 4

Syntax:
string select [start, length]
Parameters:
string: String
start: Number - string position to start selection from. 0 denotes the first character of the string, 1 the second, etc. If passed number has decimal places it gets rounded down for fractions less than or equal .5, otherwise it gets rounded up
length: Number - (Optional, default string's length) number of characters to select
Return Value:
String
Substring version of select operates with the ANSI charset; if Unicode support is desired, see forceUnicode.

Syntax 5

Syntax:
array select [start, count]
Parameters:
array: Array
start: Number - array index to start selection from
count: Number - Number of array elements to select. If the selected range exceeds source array boundaries, selection will be made up to the last element of the array. Since v2.14 'count' is optional, if omitted the selection is made from 'start' until the end of array.
Return Value:
Array - a new array from selection

Syntax 6

Syntax:
array select expression
Parameters:
array: Array
expression: Code - expression that is expected to return Boolean or Nothing. If true is returned, the original array value of currently tested element _x will be added to the output array
Return Value:
Array - a new array of all elements from the original array that satisfied expression condition

Examples

Example 1:
["a", "b", "c", "d"] select 2; // result is "c" position player select 2; // result is Z coordinate of player position
Example 2:
["", currentWeapon player] select alive player; // if player is dead, "" is selected
Example 3:
(configFile >> "cfgVehicles" >> typeOf vehicle player >> "Turrets") select 0 >> "gunnerAction";
Example 4:
hint str ("japa is the man!" select [8]); // the man! hint str ("japa is the man!" select [0, 7]); // japa is
Example 5:
hint str ([1,2,3,4,5,6] select [1, 4]); // [2,3,4,5]
Example 6:
_even = [1,2,3,4,5,6,7,8,9,0] select { _x % 2 == 0 }; // returns [2, 4, 6, 8, 0]
Example 7:
JavaScript endsWith() alternative:
private _fnc_endsWith = { params ["_string", "_endswith"]; _string select [count _string - count _endswith] isEqualTo _endswith }; ["Arma 3", "3"] call _fnc_endsWith; // true ["Arma 3", "4"] call _fnc_endsWith; // false

Additional Information

See also:
# selectRandom selectRandomWeighted set resize reverse in find findIf toArray toString forEach count deleteAt deleteRange append sort param params splitString joinString pushBack pushBackUnique apply forceUnicode

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
General Barron
Posted on Mar 03, 2009 - 02:02 (UTC)
When combined with the count command, this can be used to read all entries out of a config; even when you don't know exactly how many entries there will be. See the notes under count for more info.
Killzone Kid
Posted on Sep 28, 2013 - 00:53 (UTC)
Rounding of fractions with select is not the same as when you use round command:
_roundThis = 0.5; hint str ([0,1] select _roundThis); // 0 hint str ([0,1] select round _roundThis); // 1
Pierre MGI
Posted on Jul 14, 2016 - 04:18 (UTC)
You can substract array from array using select:
_array = [[1], [2], [3]]; _sub = [2]; _array - _sub; // [[1], [2], [3]] _array select { !(_x isEqualTo _sub) }; // [[1], [3]] [[1],[2],[2],[2],[2],[3]] select { !(_x isEqualTo _sub) }; // [[1], [3]]
Killzone Kid
Posted on Jun 22, 2015 - 23:23 (UTC)
Usually when select tries to pick up element out of range, Arma throws "division by zero" error. However there are exceptions. Basically as long as index of element you are selecting is less then or equal to array size, you will get no error.
[] select 0; // ok, result is nil [1,2,3] select 3; // ok, result is nil [1,2,3] select 4; // division by zero
Commy2
Posted on Nov 12, 2016 - 22:36 (UTC)
It is not safe to escape the code block of alternative syntax #5 with exitWith, breakOut etc:
x3 = [1,2,3,4,5] select { if (_x == 3) exitWith { false; }; true }; // could be expected to be: x3 = [1,2,4,5] // actual result: x3 = false
Igneous01
Posted on Feb 14, 2017 - 16:26 (UTC)
Syntax 5 is the equivalent of passing in a predicate that returns a boolean. In SQF, a piece of code will always return what the last executed command returned.
myAliveUnits = allUnits select { alive _x }; // alive returns a boolean, the last statement run was alive _x, // therefore this piece of code will return a true/false to the select command myEastGroups = allGroups select { side _x == east }; // returns all east groups my4ManGroups = allGroups select { count units _x == 4 }; // returns all groups that have 4 men in them unitsThatDetectedMe = allUnits select { _x knowsAbout player > 0.1 }; // returns a list of units that have detected the player