forEachReversed: Difference between revisions

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(Created page with "{{RV|type=command |game1= arma3 |version1= 2.14 |branch= dev |gr1= Arrays |descr= Interates over given array from last index to first index. |s1= code {{subst:PAGENAMEE...")
 
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{{RV|type=command
{{RV|type=command


|game1= arma3
|game1=arma3
|version1= 2.14
|version1= 2.14


|branch= dev
|branch= dev


|gr1= Arrays
|gr1=Program Flow
|gr2=Arrays


|descr= Interates over given array from last index to first index.
|descr= Executes the given command(s) on every item of an [[Array]] in reversed order, compared to [[forEach]].


|s1= code [[forEachReversed]] array
|s1= code [[forEachReversed]] array


|p1= code: [[Code]] - Code applied to each array entry
|p1= code: [[Code]] to execute on each array item - available variables:
* {{hl|[[Magic Variables#x|_x]]}}: iterated item
* {{hl|[[Magic Variables#x|_x]]}}: iterated item
* {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: item's index
* {{hl|[[Magic Variables#forEachIndex|_forEachIndex]]}}: item's index
Line 20: Line 21:
|r1= [[Anything]] - Will return the value of last executed statement
|r1= [[Anything]] - Will return the value of last executed statement


|x1= <sqf>{
|x1= This command lets you easily iterate through an array from last to first element without modifying the array itself with [[reverse]] or using [[for]] loop with negative [[step]].
    if (isNull _x) then { _array deleteAt _forEachIndex };
<sqf>
} forEachReverse _array;</sqf>
// Will show numbers from 5 to 1 in the chat
{ systemChat str _x } forEachReversed [1,2,3,4,5];
</sqf>


|seealso= [[forEachIndex]]
|x2= Can be useful to walk through array while also deleting items from it, which you couldn't do with [[forEach]] as easily:
<sqf>
private _array = [1,1,2,2,1,1,2,2];
{
    if (_x == 2) then { _array deleteAt _forEachIndex };
} forEachReversed _array;
// _array will be [1,1,1,1] here
</sqf>
Won't work with [[forEach]] as you might expect it:
<sqf>
private _array = [1,1,2,2,1,1,2,2];
{
    if (_x == 2) then { _array deleteAt _forEachIndex };
} forEach _array;
// _array will be [1,1,2,1,1,2] here
</sqf>
 
|x3= Deleting items from array with more complex condition than just comparison.
<sqf>
{
    if (!alive _x) then { _vehicles deleteAt _forEachIndex };
} forEachReverse _vehicles;
</sqf>
 
|seealso= [[Control Structures]] [[forEach]] [[for]] [[apply]] [[while]] [[select]] [[findIf]] [[count]] [[deleteAt]] [[reverse]]
}}
}}

Revision as of 10:11, 2 April 2023

Hover & click on the images for description
Only available in Development branch(es) until its release with Arma 3 patch v2.14.

Description

Description:
Executes the given command(s) on every item of an Array in reversed order, compared to forEach.
Groups:
Program FlowArrays

Syntax

Syntax:
code forEachReversed array
Parameters:
code: Code to execute on each array item - available variables:
array: Array - The array to iterate over
Return Value:
Anything - Will return the value of last executed statement

Examples

Example 1:
This command lets you easily iterate through an array from last to first element without modifying the array itself with reverse or using for loop with negative step.
// Will show numbers from 5 to 1 in the chat { systemChat str _x } forEachReversed [1,2,3,4,5];
Example 2:
Can be useful to walk through array while also deleting items from it, which you couldn't do with forEach as easily:
private _array = [1,1,2,2,1,1,2,2]; { if (_x == 2) then { _array deleteAt _forEachIndex }; } forEachReversed _array; // _array will be [1,1,1,1] here
Won't work with forEach as you might expect it:
private _array = [1,1,2,2,1,1,2,2]; { if (_x == 2) then { _array deleteAt _forEachIndex }; } forEach _array; // _array will be [1,1,2,1,1,2] here
Example 3:
Deleting items from array with more complex condition than just comparison.
{ if (!alive _x) then { _vehicles deleteAt _forEachIndex }; } forEachReverse _vehicles;

Additional Information

See also:
Control Structures forEach for apply while select findIf count deleteAt reverse

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