select: Difference between revisions

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|r6= [[Array]] - a <u>new array</u> of all elements from the original array that satisfied expression condition
|r6= [[Array]] - a <u>new array</u> of all elements from the original array that satisfied expression condition


|x1= <code>["a", "b", "c", "d"] [[select]] 2; {{cc|result is "c"}}
|x1= <code>["a", "b", "c", "d"] [[select]] 2; {{cc|result is "c"}}

Revision as of 23:40, 10 June 2021

Hover & click on the images for description

Description

Description:
Description needed
Groups:
ArraysStringsConfig

Syntax 1

Syntax:
Syntax needed
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.
Return Value:
Return value needed

Syntax 2

Syntax:
array select boolean
Parameters:
array: Array
boolean: Boolean - true => 1, false => 0
Return Value:
Anything - a reference to array element given by its index (false - 0, true - 1)

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] Template:Since
Parameters:
string: String
[start, length]: Array
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 (optional): Number - Number of the string characters to select. If "length" is omitted, selection will be made from "start" to the end of the string.
Return Value:
String

Syntax 5

Syntax:
array select [start, count] Template:Since
Parameters:
array: Array
[start, count]: 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.
Return Value:
Array - a new array from selection

Syntax 6

Syntax:
array select expression Template:Since
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

Additional Information

See also:
a hash bselectRandomselectRandomWeightedsetresizereverseinfindfindIftoArraytoStringforEachcountdeleteAtdeleteRangeappendsortparamparamssplitStringjoinStringpushBackpushBackUniqueapplyforceUnicode

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 3 March 2009
General Barron
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.
Posted on 27 Sep, 2013
Killzone_Kid
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
Posted on 14 juil, 2016
Pierre MGI
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]];
Posted on June 22, 2015 - 23:23 (UTC)
Killzone Kid
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
Posted on November 12, 2016 - 22:36 (UTC)
Commy2
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
Posted on February 14, 2017 - 16:26 (UTC)
Igneous01
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 groups that are side EAST 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
Posted on May 28, 2017 - 13:51 (UTC)
IT07
Very simple example of how to report about the status of the player: [ "Player is dead.", "Player is alive" ] select ( alive player ) returns "Player is alive" because ( alive player ) returned true. If ( alive player ) returned false, the first element (0) would have been returned. That is a great way of reporting about something without having to write a complicated it then else statement.
Posted on April 14, 2018 - 13:06 (UTC)
bloodwyn1756
Since 1.82 "#" symbol can be used to select from an array. It's shorter to write and has higher priority than math functions.