forEach: Difference between revisions

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{{Command|Comments=
{{Command


| ofp |Game name=
| ofp


|gr1= Program Flow |GROUP1=
|gr1= Program Flow


|1.00|Game version=
|1.00


| Executes the given command(s) on every item of an array.<br>
| Executes the given command(s) on every item of an array.<br>
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In {{arma2}} and later, the variable [[_x]] is always local to the [[forEach]] block so it is safe to nest them.<br>
In {{arma2}} and later, the variable [[_x]] is always local to the [[forEach]] block so it is safe to nest them.<br>
{{Since|arma3|2.01|y}} the [[HashMap]] variant also provides a _y variable for the Value in the key-value pair.
{{Since|arma3|2.01|y}} the [[HashMap]] variant also provides a _y variable for the Value in the key-value pair.
|DESCRIPTION=


| code [[forEach]] array |SYNTAX=
 
| code [[forEach]] array


|p1= code:
|p1= code:
* [[String]] ({{ofp}}&nbsp;/&nbsp;{{arma1}})
* [[String]] ({{ofp}}&nbsp;/&nbsp;{{arma1}})
* [[Code]] ({{arma1}} and later) |PARAMETER1=
* [[Code]] ({{arma1}} and later)


|p2= array: [[Array]] - the array to iterate |PARAMETER2=
|p2= array: [[Array]] - the array to iterate


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


| s2= code [[forEach]] hashMap |SYNTAX4=
| s2= code [[forEach]] hashMap


| p21= code: [[Code]] |Parameter21=
| p21= code: [[Code]] |Parameter21=
| p22= hashMap : [[HashMap]] - The HashMap to iterate through |Parameter22=
| p22= hashMap : [[HashMap]] - The HashMap to iterate through |Parameter22=


| r2= [[Anything]] - will return the value of last executed statement |RETURNVALUE2=
| r2= [[Anything]] - will return the value of last executed statement


   
   
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{ [[_x]] [[setDamage]] 1 } [[forEach]] [[units]] [[group]] [[player]];</code>
{ [[_x]] [[setDamage]] 1 } [[forEach]] [[units]] [[group]] [[player]];</code>
<code>{{codecomment|; SQS}}
<code>{{codecomment|; SQS}}
"[[_x]] [[setDammage]] 1" [[forEach]] [[units]] [[group]] [[player]]</code> |EXAMPLE1=
"[[_x]] [[setDammage]] 1" [[forEach]] [[units]] [[group]] [[player]]</code>


|x2= This command can also easily be used to execute a single command multiple times without respect to the array items.
|x2= This command can also easily be used to execute a single command multiple times without respect to the array items.
<code>{ [[player]] [[addMagazine]] "30Rnd_556x45_Stanag"; } [[forEach]] [1, 2, 3, 4];</code> |EXAMPLE2=
<code>{ [[player]] [[addMagazine]] "30Rnd_556x45_Stanag"; } [[forEach]] [1, 2, 3, 4];</code>


|x3= You can also use multiple commands in the same block:
|x3= You can also use multiple commands in the same block:
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     [[removeAllWeapons]] [[Magic Variables|_x]];
     [[removeAllWeapons]] [[Magic Variables|_x]];
     [[doStop]] [[Magic Variables|_x]];
     [[doStop]] [[Magic Variables|_x]];
} [[forEach]] [[units]] [[group]] [[this]];</code> |EXAMPLE3=
} [[forEach]] [[units]] [[group]] [[this]];</code>


|x4= To get the index of a [[forEach]] loop, use [[_forEachIndex]]:
|x4= To get the index of a [[forEach]] loop, use [[_forEachIndex]]:
<code>{ [[systemChat]] [[format]] ["%1", _forEachIndex]; } [[forEach]] [1,2,3]; {{cc|will return: "0", "1", "2" in [[systemChat]] messages}}</code> |EXAMPLE4=
<code>{ [[systemChat]] [[format]] ["%1", _forEachIndex]; } [[forEach]] [1,2,3]; {{cc|will return: "0", "1", "2" in [[systemChat]] messages}}</code>


|x5= Iterating a [[HashMap]] [[_forEachIndex]]:
|x5= Iterating a [[HashMap]] [[_forEachIndex]]:
<code>{ [[systemChat]] [[format]] ["%1-%2", _x, _y]; } [[forEach]] createHashMapFromArray [[1,"a"], [2,"b"]]; {{cc|will return: "1-a", "2-b" in [[systemChat]] messages}}</code> |EXAMPLE5=
<code>{ [[systemChat]] [[format]] ["%1-%2", _x, _y]; } [[forEach]] createHashMapFromArray [[1,"a"], [2,"b"]]; {{cc|will return: "1-a", "2-b" in [[systemChat]] messages}}</code>


| [[set]], [[resize]], [[pushBack]], [[pushBackUnique]], [[apply]], [[reverse]], [[select]], [[in]], [[find]], [[findIf]], [[toArray]], [[toString]], [[count]], [[deleteAt]], [[deleteRange]], [[append]], [[sort]], [[param]], [[params]], [[arrayIntersect]], [[Control Structures]], [[splitString]], [[joinString]] |SEEALSO=
| [[set]], [[resize]], [[pushBack]], [[pushBackUnique]], [[apply]], [[reverse]], [[select]], [[in]], [[find]], [[findIf]], [[toArray]], [[toString]], [[count]], [[deleteAt]], [[deleteRange]], [[append]], [[sort]], [[param]], [[params]], [[arrayIntersect]], [[Control Structures]], [[splitString]], [[joinString]]
}}
}}



Revision as of 00:35, 18 January 2021

Hover & click on the images for description

Description

Description:
Executes the given command(s) on every item of an array.
The array items are represented by the magic variable _x. The array indices are represented by _forEachIndex.
In Arma 2 and later, the variable _x is always local to the forEach block so it is safe to nest them.
Template:Since the HashMap variant also provides a _y variable for the Value in the key-value pair.
Groups:
Program Flow

Syntax

Syntax:
code forEach array
Parameters:
code:
  • String (Operation Flashpoint / Armed Assault)
  • Code (Armed Assault and later)
array: Array - the array to iterate
Return Value:
Anything - will return the value of last executed statement

Alternative Syntax

Syntax:
code forEach hashMap
Parameters:
code: Code
hashMap : HashMap - The HashMap to iterate through
Return Value:
Anything - will return the value of last executed statement

Examples

Example 1:
// SQF { _x setDamage 1 } forEach units group player; ; SQS "_x setDammage 1" forEach units group player
Example 2:
This command can also easily be used to execute a single command multiple times without respect to the array items. { player addMagazine "30Rnd_556x45_Stanag"; } forEach [1, 2, 3, 4];
Example 3:
You can also use multiple commands in the same block: { _x setCaptive true; removeAllWeapons _x; doStop _x; } forEach units group this;
Example 4:
To get the index of a forEach loop, use _forEachIndex: { systemChat format ["%1", _forEachIndex]; } forEach [1,2,3]; // will return: "0", "1", "2" in systemChat messages
Example 5:
Iterating a HashMap _forEachIndex: { systemChat format ["%1-%2", _x, _y]; } forEach createHashMapFromArray [[1,"a"], [2,"b"]]; // will return: "1-a", "2-b" in systemChat messages

Additional Information

See also:
setresizepushBackpushBackUniqueapplyreverseselectinfindfindIftoArraytoStringcountdeleteAtdeleteRangeappendsortparamparamsarrayIntersectControl StructuressplitStringjoinString

Notes

Report bugs on the Feedback Tracker and/or discuss them on the Arma Discord.
Only post proven facts here! Add Note

Notes

Posted on July 20, 2010
Kronzky
If arrays are used in forEach loops, _x uses them by reference, so any changes to _x will be applied to the original: _arr1 = [1,2,3]; _arr2 = [6,7,8]; { _x set [1,"x"] } forEach [_arr1,_arr2]; will change _arr1 to [1,"x",3], and _arr2 to [6,"x",8].

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Posted on August 29, 2014 - 22:23 (UTC)
Fett Li
forEach returns any (the last passed value will be the return value or just Nothing, depends on the function called). _var = {_x} forEach [nil,"s",objNull,configFile ]; // return bin\config.bin _var = {_x setCaptive true} forEach allUnits; // return nothing
Posted on September 20, 2014
Mossarelli
Using the foreach loop, since there are no variable for the index like say the for-do loop, there is a variable that you can use to check the index of the foreach loop. { if (_forEachIndex == 1) then { // Copilot _x addUniform "U_B_Soldier_VR"; } else { // Adams [_x, "B_Soldier_TL_F"] call BIS_fnc_loadInventory; _x addUniform "U_B_Soldier_VR"; _x setIdentity "Bootcamp_B_Adams"; }; } forEach _crew; So when the array is past from _crew to the loop, index 1 (which is the second element) is the copilot of the "B_Heli_Light_01_F" and he will get "U_B_Soldier_VR" as a uniform. While the pilot which is index 0 (first element), will get the same uniform but will get the loadout of "B_Soldier_TL_F" and the identity of "Bootcamp_B_Adams".
Posted on January 2, 2015 - 22:35 (UTC)
Heeeere's Johnny!
Using exitWith inside a forEach loop will make forEach actually return something, namely whatever the exitWith returns: _result = { if(_x isEqualTo 3) exitWith {"Hello"} } forEach [1,2,3,4,5]; //_result = "Hello"
Posted on November 28, 2017 - 13:46 (UTC)
dedmen
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 _forEachIndex = 0; while {_forEachIndex < count _array} do { (_array select _forEachIndex) call code; _forEachIndex = _forEachIndex + 1; } 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.