forEach: Difference between revisions
Jump to navigation
Jump to search
mNo edit summary |
Lou Montana (talk | contribs) m (Text replacement - "Samatra" to "Sa-Matra") |
||
(115 intermediate revisions by 28 users not shown) | |||
Line 1: | Line 1: | ||
{{RV|type=command | |||
|game1= ofp | |||
|version1= 1.00 | |||
|game2= ofpe | |||
|version2= 1.00 | |||
|game3= arma1 | |||
|version3= 1.00 | |||
|game4= arma2 | |||
|version4= 1.00 | |||
|game5= arma2oa | |||
|version5= 1.50 | |||
|game6= tkoh | |||
|version6= 1.00 | |||
|game7= arma3 | |||
|version7= 0.50 | |||
|gr1= Program Flow | |||
|gr2= Arrays | |||
|gr3= 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 {{Link|#Example 8}}).}} | |||
|s1= code [[forEach]] array | |||
|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 | |||
* {{GVI|arma2oa|1.55|size= 0.75}} {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: item's index | |||
|p2= array: [[Array]] - the array to iterate over | |||
|r1= [[Anything]] - will return the value of last executed statement | |||
|s2= code [[forEach]] hashMap | |||
"' | |s2since= arma3 2.02 | ||
|p21= code: [[Code]] - code applied to each key-value pair - available variables: | |||
* {{hl|[[Magic Variables#x|_x]]}}: key | |||
* {{hl|[[Magic Variables#x|_y]]}}: value | |||
* {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: iteration number | |||
|p22= hashMap : [[HashMap]] - the HashMap to iterate over | |||
|r2= [[Anything]] - will return the value of last executed statement | |||
|x1= <sqf> | |||
// SQF | |||
{ _x setDamage 1 } forEach units player; | |||
</sqf> | |||
<sqs> | |||
; SQS | |||
"_x setDammage 1" forEach units player | |||
</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]] | |||
<sqf> | |||
{ player addMagazine "30Rnd_556x45_Stanag" } forEach [1, 2, 3, 4]; | |||
// equivalent to | |||
for "_i" from 1 to 4 do { player addMagazine "30Rnd_556x45_Stanag" }; | |||
</sqf> | |||
|x3= You can also use multiple commands in the same block: | |||
<sqf> | |||
{ | |||
_x setCaptive true; | |||
removeAllWeapons _x; | |||
doStop _x; | |||
} forEach units group this; | |||
</sqf> | |||
|x4= To get the index of a [[forEach]] loop, use [[Magic Variables#forEachIndex|_forEachIndex]]: | |||
<sqf>{ systemChat str _forEachIndex; } forEach ["a", "b", "c"]; // will return: "0", "1", "2" in systemChat messages</sqf> | |||
|x5= Iterating a [[HashMap]]'s [[Magic Variables#forEachIndex|_forEachIndex]]: | |||
<sqf> | |||
// shows "0, k1, v1", "1, k2, v2" in systemChat messages | |||
{ | |||
systemChat format ["%1, %2, %3", _forEachIndex, _x, _y]; | |||
} forEach createHashMapFromArray [ | |||
["k1", "v1"], | |||
["k2", "v2"] | |||
]; | |||
</sqf> | |||
|x6= [[findIf]] equivalent for [[HashMap]]: | |||
<sqf> | |||
private _resultKey = { | |||
if (_y isEqualTo "wantedValue") exitWith { _x }; | |||
"" | |||
} forEach _hashmap; | |||
</sqf> | |||
|x7= Array is edited by reference: | |||
<sqf> | |||
_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"] | |||
</sqf> | |||
|x8= <sqf> | |||
{ | |||
private _verticalValue = _x; // needed, otherwise _horizontalValues' _x made this one inaccessible | |||
{ | |||
[_x, _verticalValue] call TAG_fnc_doSomething; | |||
} forEach _horizontalValues; | |||
} forEach _verticalValues; | |||
</sqf> | |||
|seealso= [[Control Structures]] [[for]] [[apply]] [[while]] [[select]] [[findIf]] [[count]] [[forEachReversed]] | |||
}} | |||
{{Note | |||
|user= Dedmen | |||
|timestamp= 20171128134600 | |||
|text= Be careful when deleting ([[deleteAt]]) elements from an Array while you iterate over it.<br> | |||
[[forEachIndex|_forEachIndex]] will not move to reflect your change.<br> | |||
The forEach code is doing the same as | |||
<sqf> | |||
private _forEachIndex = 0; | |||
while { _forEachIndex < count _array } do | |||
{ | |||
(_array select _forEachIndex) call code; | |||
_forEachIndex = _forEachIndex + 1; | |||
}; | |||
</sqf> | |||
So if you delete your current element from the array the other elements will shift forward. Meaning you skip one element.<br> | |||
Example: | |||
<sqf> | |||
_array = [1,2,3,4,5,6]; | |||
{ _array deleteAt _forEachIndex } forEach _array; | |||
</sqf> | |||
After the first iteration your Array will be [2,3,4,5,6] and the _forEachIndex will be 1.<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. | |||
}} | |||
{{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
Description
- Description:
- Executes the given command(s) on every item of an Array or a HashMap.
- Groups:
- Program FlowArraysHashMap
Syntax
- Syntax:
- code forEach array
- Parameters:
-
Game 1.00 1.00 1.00 1.50 1.00 1.00 String support Code support code: String only in Operation Flashpoint and Armed Assault, 1.00 Code since Armed Assault - available variables:
- _x: iterated item
- 1.55 _forEachIndex: item's index
- 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:
- _x: key
- _y: value
- _forEachIndex: iteration number
- hashMap : HashMap - the HashMap to iterate over
- Return Value:
- Anything - will return the value of last executed statement
Examples
- Example 1:
- 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:
- Example 7:
- Array is edited by reference:
- Example 8:
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
- 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 asSo if you delete your current element from the array the other elements will shift forward. Meaning you skip one element.private _forEachIndex = 0; while { _forEachIndex < count _array } do { (_array select _forEachIndex) call code; _forEachIndex = _forEachIndex + 1; };
Example: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.
- Posted on Apr 02, 2023 - 09:04 (UTC)
- Use new forEachReversed command for deleting array items with deleteAt. Check its examples for details.
Categories:
- Scripting Commands
- Introduced with Operation Flashpoint version 1.00
- Operation Flashpoint: New Scripting Commands
- Operation Flashpoint: Scripting Commands
- Operation Flashpoint: Elite: Scripting Commands
- ArmA: Armed Assault: Scripting Commands
- Arma 2: Scripting Commands
- Arma 2: Operation Arrowhead: Scripting Commands
- Take On Helicopters: Scripting Commands
- Arma 3: Scripting Commands
- Command Group: Program Flow
- Command Group: Arrays
- Command Group: HashMap