forEach: Difference between revisions

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|gr1= Program Flow
|gr1= Program Flow
|gr2=Arrays
|gr2= Arrays
|gr3= HashMap
|gr3= HashMap


|descr= Executes the given command(s) on every item of an [[Array]] or a [[HashMap]].
|descr= Executes the given command(s) on every item of an [[Array]] or a [[HashMap]].
{{Feature|arma2|Since {{arma2}}, the variable [[Magic Variables#x|_x]] is always [[private]] to the [[forEach]] block so it is safe to nest them (see {{HashLink|#Example 8}}).}}
{{Feature|arma2|Since {{arma2}}, the variable [[Magic Variables#x|_x]] is always [[private]] to the [[forEach]] block so it is safe to nest them (see {{Link|#Example 8}}).}}


|s1= code [[forEach]] array
|s1= code [[forEach]] array


|p1= code: [[String]] in {{ofp}} and {{arma1}}, [[Code]] since {{arma1}} - available variables:
|p1= <nowiki/>
{{{!}} class="wikitable align-center float-right"
! Game
{{!}} {{GVI|ofp|1.00}}
{{!}} {{GVI|arma1|1.00}}
{{!}} {{GVI|arma2|1.00}}
{{!}} {{GVI|arma2oa|1.50}}
{{!}} {{GVI|arma3|1.00}}
{{!}} {{GVI|tkoh|1.00}}
{{!}}-
! [[String]] support
{{!}} colspan="2" {{!}} {{Icon|checked}}
{{!}} colspan="4" {{!}} {{Icon|unchecked}}
{{!}}-
! [[Code]] support
{{!}} {{Icon|unchecked}}
{{!}} colspan="5" {{!}} {{Icon|checked}}
{{!}}}
code: [[String]] only in {{ofp}} and {{arma1}}, {{GVI|arma1|1.00|size= 0.75}} [[Code]] since {{arma1}} - available variables:
* {{hl|[[Magic Variables#x|_x]]}}: iterated item
* {{hl|[[Magic Variables#x|_x]]}}: iterated item
* {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: item's index
* {{GVI|arma2oa|1.55|size= 0.75}} {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: item's index


|p2= array: [[Array]] - The array to iterate over
|p2= array: [[Array]] - the array to iterate over


|r1= [[Anything]] - Will return the value of last executed statement
|r1= [[Anything]] - will return the value of last executed statement


|s2= code [[forEach]] hashMap
|s2= code [[forEach]] hashMap
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* {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: iteration number
* {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: iteration number


|p22= hashMap : [[HashMap]] - The HashMap to iterate over
|p22= hashMap : [[HashMap]] - the HashMap to iterate over


|r2= [[Anything]] - Will return the value of last executed statement
|r2= [[Anything]] - will return the value of last executed statement


|x1= <sqf>
|x1= <sqf>
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{ _x setDamage 1 } forEach units player;
{ _x setDamage 1 } forEach units player;
</sqf>
</sqf>
<sqf>
<sqs>
"SQS"
; SQS
"_x setDammage 1" forEach units player
"_x setDammage 1" forEach units player
</sqf>
</sqs>


|x2= This command can also easily be used to execute a single command multiple times without respect to the array items - see also [[for]]
|x2= This command can also easily be used to execute a single command multiple times without respect to the array items - see also [[for]]
Line 71: Line 89:
<sqf>
<sqf>
{
{
    _x setCaptive true;
_x setCaptive true;
    removeAllWeapons _x;
removeAllWeapons _x;
    doStop _x;
doStop _x;
} forEach units group this;
} forEach units group this;
</sqf>
</sqf>
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</sqf>
</sqf>


|seealso= [[Control Structures]] [[for]] [[apply]] [[while]] [[select]] [[findIf]] [[count]]  
|seealso= [[Control Structures]] [[for]] [[apply]] [[while]] [[select]] [[findIf]] [[count]] [[forEachReversed]]
}}
}}


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while { _forEachIndex < count _array } do
while { _forEachIndex < count _array } do
{
{
    (_array select _forEachIndex) call code;
(_array select _forEachIndex) call code;
    _forEachIndex = _forEachIndex + 1;
_forEachIndex = _forEachIndex + 1;
};
};
</sqf>
</sqf>
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So on next iteration you get the element at index 1 which will be 3. So you've just skipped the 2.<br>
So on next iteration you get the element at index 1 which will be 3. So you've just skipped the 2.<br>
So in the end you will only iterate over 1, 3 and 6.
So in the end you will only iterate over 1, 3 and 6.
}}
{{Note
|user= Sa-Matra
|timestamp= 20230402090428
|text= Use new [[forEachReversed]] command for deleting array items with [[deleteAt]]. Check its examples for details.
}}
}}

Latest revision as of 20:58, 4 July 2024

Hover & click on the images for description

Description

Description:
Executes the given command(s) on every item of an Array or a HashMap.
Arma 2
Since Arma 2, the variable _x is always private to the forEach block so it is safe to nest them (see Example 8).
Groups:
Program FlowArraysHashMap

Syntax

Syntax:
code forEach array
Parameters:
Game Logo A0.png1.00 Logo A1 black.png1.00 Logo A2.png1.00 A2 OA Logo.png1.50 Arma 3 logo black.png1.00 tkoh logo small.png1.00
String support Checked Unchecked
Code support Unchecked Checked

code: String only in Operation Flashpoint and Armed Assault, Logo A1 black.png1.00 Code since Armed Assault - available variables:

array: Array - the array to iterate over
Return Value:
Anything - will return the value of last executed statement

Alternative Syntax

Syntax:
code forEach hashMap
Parameters:
code: Code - code applied to each key-value pair - available variables:
hashMap : HashMap - the HashMap to iterate over
Return Value:
Anything - will return the value of last executed statement

Examples

Example 1:
// SQF { _x setDamage 1 } forEach units player;
; SQS "_x setDammage 1" forEach units player
Example 2:
This command can also easily be used to execute a single command multiple times without respect to the array items - see also for
{ player addMagazine "30Rnd_556x45_Stanag" } forEach [1, 2, 3, 4]; // equivalent to for "_i" from 1 to 4 do { player addMagazine "30Rnd_556x45_Stanag" };
Example 3:
You can also use multiple commands in the same block:
Example 4:
To get the index of a forEach loop, use _forEachIndex:
{ systemChat str _forEachIndex; } forEach ["a", "b", "c"]; // will return: "0", "1", "2" in systemChat messages
Example 5:
Iterating a HashMap's _forEachIndex:
// shows "0, k1, v1", "1, k2, v2" in systemChat messages { systemChat format ["%1, %2, %3", _forEachIndex, _x, _y]; } forEach createHashMapFromArray [ ["k1", "v1"], ["k2", "v2"] ];
Example 6:
findIf equivalent for HashMap:
private _resultKey = { if (_y isEqualTo "wantedValue") exitWith { _x }; "" } forEach _hashmap;
Example 7:
Array is edited by reference:
_arr1 = [1,2,3]; _arr2 = [6,7,8]; _arr3 = [0]; { _x set [1, "changed"] } forEach [_arr1, _arr2, _arr3]; // _arr1 = [1, "changed", 3] // _arr2 = [6, "changed", 8] // _arr3 = [0, "changed"]
Example 8:
{ private _verticalValue = _x; // needed, otherwise _horizontalValues' _x made this one inaccessible { [_x, _verticalValue] call TAG_fnc_doSomething; } forEach _horizontalValues; } forEach _verticalValues;

Additional Information

See also:
Control Structures for apply while select findIf count forEachReversed

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
Dedmen - c
Posted on Nov 28, 2017 - 13:46 (UTC)
Be careful when deleting (deleteAt) elements from an Array while you iterate over it.
_forEachIndex will not move to reflect your change.
The forEach code is doing the same as So if you delete your current element from the array the other elements will shift forward. Meaning you skip one element.
Example:
_array = [1,2,3,4,5,6]; { _array deleteAt _forEachIndex } forEach _array;
After the first iteration your Array will be [2,3,4,5,6] and the _forEachIndex will be 1.
So on next iteration you get the element at index 1 which will be 3. So you've just skipped the 2.
So in the end you will only iterate over 1, 3 and 6.
Sa-Matra - c
Posted on Apr 02, 2023 - 09:04 (UTC)
Use new forEachReversed command for deleting array items with deleteAt. Check its examples for details.