while: Difference between revisions

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{{Command|= Comments
{{RV|type=command
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| ofpr |= Game name
|game1= ofp
|version1= 1.85


|1.85|= Game version
|game2= ofpe
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|version2= 1.00


| First part of while construct. |= Description
|game3= arma1
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|version3= 1.00


| '''while ''condition''''' |= Syntax
|game4= arma2
|version4= 1.00


|p1= condition: [[Code]] |= Parameter 1
|game5= arma2oa
|version5= 1.50


| [[While Type]] |= Return value
|game6= tkoh
____________________________________________________________________________________________
|version6= 1.00
 
||x1= <code>while {x<10} [[do]] {x<nowiki>=</nowiki>x+1} </code>|= Example 1


||x2=A more practical example: To repair all the members of a group to such a level that they are all able to stand up: <code><nowiki>{</nowiki>while <nowiki>{</nowiki>([[not]] [[canStand]] _x) [[and]] [[alive]] _x)<nowiki>}</nowiki> [[do]] <nowiki>{</nowiki>_x [[setDammage]] ([[getDammage]] _x) - 0.01<nowiki>}}</nowiki>[[forEach]] units
|game7= arma3
[[group]] unitname </code> |= Example 2
|version7= 0.50
____________________________________________________________________________________________
|  |= See also


|gr1= Program Flow
|descr= Repeats [[Code]] while the given condition is [[true]]. A part of [[while]]-[[do]] construct.
{{Feature|important|
* A [[while]] loop does not have any suspension, meaning that if used in [[Scheduler#Scheduled_Environment|scheduled environment]] without any suspension ([[sleep]] or [[uiSleep]]) the code will run multiple times per frame and consumes the 3 ms per frame scheduler execution limit. This should be avoided if not intended (see {{Link|#Example 3}}).
* In [[Scheduler#Unscheduled_Environment|non-scheduled environment]], [[while]] [[do]] loop is limited to 10,000 iterations, after which it exits even if condition is still [[true]].
}}
}}
|s1= [[while]] condition
|p1= condition: [[Code]]
|r1= [[While Type]]
|x1= <sqf>while { a < b } do { a = a + 1 };</sqf>


<h3 style="display:none">Notes</h3>
|x2= A practical example: Repair all members of a group to such a level that they are able to stand up:
<dl class="command_description">
<sqf>
<!-- Note Section BEGIN -->
{
if (alive _x) then
{
while { not canStand _x } do
{
_x setDamage (damage _x - 0.01);
};
};
} forEach units group unitname;
</sqf>


<!-- Note Section END -->
|x3= <sqf>
</dl>
0 spawn {
// warning: while loop without suspension executes multiple times per frame
private _counter = 0;
private _endTime = diag_tickTime + 5;
private _frameNo = diag_frameNo;
while { diag_tickTime < _endTime } do
{
_counter = _counter + 1;
};
// in an empty mission, the _counter may go well over 2000 times per frame!
hint format ["Average Execution: %1 times per frame", _counter / (diag_frameNo - _frameNo)];


<h3 style="display:none">Bottom Section</h3>
// with suspension
private _counter = 0;
private _endTime = diag_tickTime + 5;
private _frameNo = diag_frameNo;
while { diag_tickTime < _endTime } do
{
_counter = _counter + 1;
uiSleep 0.001; // waits at least 1 frame
};
// _counter says one per frame, as expected
hint format ["Average Execution: %1 times per frame", _counter / (diag_frameNo - _frameNo)];
};
</sqf>


|seealso= [[Control Structures]] [[waitUntil]] [[for]] [[do]]
}}


[[Category:Scripting Commands|WHILE]]
{{Note
[[Category:Scripting Commands OFP 1.96|WHILE]]
|user= Kronzky
[[Category:Scripting Commands ArmA|WHILE]]
|timestamp= 20080514084000
[[Category:Armed Assault: Control Flows|WHILE]]
|text= The boolean code that is used to evaluate the while condition can be preceded by code that executes a regular command.
<sqf>while { _a =_a + 1; _a < 10 } do { /* ... */ };</sqf>
}}

Latest revision as of 21:24, 2 September 2024

Logo A0.png1.85ofpe logo.png1.00Logo A1 black.png1.00Logo A2.png1.00A2 OA Logo.png1.50tkoh logo small.png1.00Arma 3 logo black.png0.50
Hover & click on the images for description

Description

Description:
Repeats Code while the given condition is true. A part of while-do construct.
⚠
  • A while loop does not have any suspension, meaning that if used in scheduled environment without any suspension (sleep or uiSleep) the code will run multiple times per frame and consumes the 3 ms per frame scheduler execution limit. This should be avoided if not intended (see Example 3).
  • In non-scheduled environment, while do loop is limited to 10,000 iterations, after which it exits even if condition is still true.
Groups:
Program Flow

Syntax

Syntax:
while condition
Parameters:
condition: Code
Return Value:
While Type

Examples

Example 1:
while { a < b } do { a = a + 1 };
Example 2:
A practical example: Repair all members of a group to such a level that they are able to stand up:
{ if (alive _x) then { while { not canStand _x } do { _x setDamage (damage _x - 0.01); }; }; } forEach units group unitname;
Example 3:
0 spawn { // warning: while loop without suspension executes multiple times per frame private _counter = 0; private _endTime = diag_tickTime + 5; private _frameNo = diag_frameNo; while { diag_tickTime < _endTime } do { _counter = _counter + 1; }; // in an empty mission, the _counter may go well over 2000 times per frame! hint format ["Average Execution: %1 times per frame", _counter / (diag_frameNo - _frameNo)]; // with suspension private _counter = 0; private _endTime = diag_tickTime + 5; private _frameNo = diag_frameNo; while { diag_tickTime < _endTime } do { _counter = _counter + 1; uiSleep 0.001; // waits at least 1 frame }; // _counter says one per frame, as expected hint format ["Average Execution: %1 times per frame", _counter / (diag_frameNo - _frameNo)]; };

Additional Information

See also:
Control Structures waitUntil for do

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
Kronzky - c
Posted on May 14, 2008 - 08:40 (UTC)
The boolean code that is used to evaluate the while condition can be preceded by code that executes a regular command.
while { _a =_a + 1; _a < 10 } do { /* ... */ };
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