switch do: Difference between revisions

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(Moved some of the notes into the description. Removed old notes which are now part of either the description or the examples. Formatted the code in the notes.)
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If a case has no code block, the code of the next case will automatically be executed. This makes it possible to formulate a logical '''"or"''' for cases which otherwise would contain the exact same code. (See example 4 below)<br>
If a case has no code block, the code of the next case will automatically be executed. This makes it possible to formulate a logical '''"or"''' for cases which otherwise would contain the exact same code. (See example 4 below)<br>
The [[default]] block will be executed '''only if''' no case matches, no matter at which position inside the switch it is. It is not a case, and will '''never''' be entered by fallthrough.<br>
The [[default]] block will be executed '''only if''' no case matches, no matter at which position inside the switch it is. It is not a case, and will '''never''' be entered by fallthrough.<br>
<br>
 
''switch'' returns whatever the return value of the executed case block is. If the condition is not matched by any case and there is no default, it returns [[true]]. |DESCRIPTION=
{{Informative|[[String]] comparison is case-sensitive. Use [[toUpper]], [[toLower]], [[toLowerANSI]] or [[toUpperANSI]] to force all [[String|strings]] to the same case.}}</br>
{{Informative|If no [[default]] block is provided and no [[case]] is matched, the default value [[true]] is returned. Otherwise it returns whatever the valid case block returns.}}
|DESCRIPTION=
____________________________________________________________________________________________
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}}
}}
[[Category:Scripting Commands|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands Armed Assault|{{uc:{{PAGENAME}}}}]]


<h3 style="display:none">Notes</h3>
<h3 style="display:none">Notes</h3>
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<dt class="note">[[User:ColonelSandersLite|ColonelSandersLite]]<dd class="note"><br>
<dt class="note">[[User:ColonelSandersLite|ColonelSandersLite]]<dd class="note"><br>
Be careful of the parenthesis around the variable you're switching on.  If you accidentally use braces instead (ex: switch {_myVar} do{...), it won't error, but will always return default.<br>
Be careful of the parenthesis around the variable you're switching on.  If you accidentally use braces instead (ex: switch {_myVar} do{...), it won't error, but will always return default.<br>
<dd class="notedate">Posted on 11 Aug, 2008
<dt class="note">[[User:Dr_Eyeball|Dr_Eyeball]]<dd class="note">
Using [[switch]] with strings is case-sensitive, (unlike string comparisons).
<dd class="notedate">Posted on 12 Aug, 2008
<dt class="note">[[User:General_Barron|General Barron]]<dd class="note">
To be safe about the case sensitivity issue, use the [[toLower]] or [[toUpper]] command to force all strings to a certain case.


<dd class="notedate">Posted on 06 Oct, 2009
<dd class="notedate">Posted on 06 Oct, 2009
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<!-- Note Section END -->
<!-- Note Section END -->
</dl>
</dl>
[[Category:Scripting Commands|{{uc:{{PAGENAME}}}}]]
[[Category:Scripting Commands Armed Assault|{{uc:{{PAGENAME}}}}]]


<!-- CONTINUE Notes -->
<!-- CONTINUE Notes -->
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<br>Sometimes, and I'm unsure why, numbers are treated differently (A2OA 1.63) with quote-wraps that worked  
<br>Sometimes, and I'm unsure why, numbers are treated differently (A2OA 1.63) with quote-wraps that worked  
<br>in earlier code now not working unless quote-wraps are removed, with otherwise identical code.
<br>in earlier code now not working unless quote-wraps are removed, with otherwise identical code.
<br><code>
<br>
_number1 = (floor random 10)
<code>_number1 [[=]] ([[floor]] [[random]] 10)
switch (_number1) do
[[switch]] (_number1) [[do]]
{
{
  case "0":
  [[case]] "0"[[:]]
  {
  {
   _vehicle setobjecttexture[0,"\mymodpath\textures\num1.paa"];
   _[[vehicle]] [[set]]objecttexture[0,"\mymodpath\textures\num1.paa"];
  };
  };
//etc
//etc
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<br>
<br>
<code>
<code>
switch (_number1) do
[[switch]] (_number1) [[do]]
{
{
  case 0:
  [[case]] 0[[:]]
  {
  {
   _vehicle setobjecttexture[0,"\mymodpath\textures\num1.paa"];
   _[[vehicle]] [[set]]objecttexture[0,"\mymodpath\textures\num1.paa"];
  };
  };
//etc
//etc
};
};
</code>
</code>
</dd>
</dl>
<!-- DISCONTINUE Notes -->
<!-- CONTINUE Notes -->
<dl class="command_description">
<dd class="notedate">Posted on December 13, 2014 - 22:41 (UTC)</dd>
<dt class="note">[[User:Commy2|Commy2]]</dt>
<dd class="note">
As of Arma 3 v1.36, switch returns true (BOOL) if the condition doesn't match any case and no default block is defined.<br>
<br>
switch (0) do {case (1): {"one"};}<br>
-> true
</dd>
</dl>
<!-- DISCONTINUE Notes -->
<!-- CONTINUE Notes -->
<dl class="command_description">
<dd class="notedate">Posted on December 14, 2014 - 04:18 (UTC)</dd>
<dt class="note">[[User:DreadedEntity|DreadedEntity]]</dt>
<dd class="note">
Function names can be used in place of code, as shown in Example 3.
</dd>
</dd>
</dl>
</dl>
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You are able to call code within the switch statements, such as:
You are able to call code within the switch statements, such as:


<code>_myFunc = {
<code>_myFunc [[=]] {
     systemChat "0";
     [[systemChat]] "0";
     case 1: {systemChat "1"};
     [[case]] 1: {[[systemChat]] "1"};
     systemChat "2";
     [[systemChat]] "2";
};
};


_myParameter = 1;
_myParameter [[=]] 1;


switch (_myParameter) do {
[[switch]] (_myParameter) [[do]] {
     _myParameter call _myFunc;
     _myParameter [[call]] _myFunc;
     case 1: {systemChat "4"};
     [[case]] 1: {[[systemChat]] "4"};
     systemChat "3";
     [[systemChat]] "3";
     default {systemChat "-1";};
     [[default]] {[[systemChat]] "-1";};
};
};</code>
 
// 0
// 3
// 1</code>


However the order in which it is executed is difficult to make sense of, see the code comment.
However the order in which it is executed is difficult to make sense of, see the code comment.

Revision as of 14:37, 1 November 2020

-wrong parameter ("Arma") defined!-1.00
Hover & click on the images for description

Description

Description:
Checks if the given parameter matches any case. If so, the code block of that case will be executed. After that the switch ends so no further cases will be checked.

If a case has no code block, the code of the next case will automatically be executed. This makes it possible to formulate a logical "or" for cases which otherwise would contain the exact same code. (See example 4 below)
The default block will be executed only if no case matches, no matter at which position inside the switch it is. It is not a case, and will never be entered by fallthrough.
String comparison is case-sensitive. Use toUpper, toLower, toLowerANSI or toUpperANSI to force all strings to the same case.

If no default block is provided and no case is matched, the default value true is returned. Otherwise it returns whatever the valid case block returns.
Groups:
Program Flow

Syntax

Syntax:
switch do block
Parameters:
switch: Switch Type
block: Code
Return Value:
Anything or true

Examples

Example 1:
switch (_a) do { case 1 : { /*...code...*/ }; case 2 : { /*...code...*/ }; default { /*...code...*/ }; };
switch (_condition) do { case 1: { hint "1" }; case 2: { hint "2" }; default { hint "default" }; };
switch (_condition) do { case "string1"; case "string2": { hint "string1 or string2" }; case "string3"; case "string4": { hint "string3 or string4" }; default { hint "default" }; };
Example 2:
_color = switch (side player) do { case west: { "ColorGreen" }; case east: { "ColorRed" }; };
Example 3:
_fn_moveForward = { /*...code...*/ }; _fn_moveBackward = { /*...code...*/ }; _fn_invalidKey = { /*...code...*/ }; switch true do { case (_dikCode in actionKeys "MoveForward"): _fn_moveForward; case (_dikCode in actionKeys "MoveBackward"): _fn_moveBackward; default _fn_invalidKey; };
Example 4:
switch _var do { case "0"; default { hint str ["default", _var] }; case "3": { hint str ["3", _var] }; case "1"; case "4"; case "2": { hint str ["2", _var] }; };
_var = "0"; //-> ["3", "0"]
_var = "1"; //-> ["2", "1"]
_var = "2"; //-> ["2", "2"]
_var = "3"; //-> ["3", "3"]
_var = "4"; //-> ["2", "4"]
_var = "5"; //-> ["default", "5"]

Additional Information

See also:
Control Structuresa:bcasedefault

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

Notes

Posted on 07 Aug, 2008
ColonelSandersLite

Be careful of the parenthesis around the variable you're switching on. If you accidentally use braces instead (ex: switch {_myVar} do{...), it won't error, but will always return default.
Posted on 06 Oct, 2009
Iva
It's possible to use Boolean value as a switch and Code as case. One thing to take special care in such case is that code must be in parentheses. Example: switch (true) do { case (_boolVar): {someCode}; case (unit1 distance unit2 > 5): {someCode}; };
Posted on November 6, 2014 - 16:33 (UTC)
Eggbeast
BEWARE:
Sometimes, and I'm unsure why, numbers are treated differently (A2OA 1.63) with quote-wraps that worked
in earlier code now not working unless quote-wraps are removed, with otherwise identical code.
_number1 = (floor random 10) switch (_number1) do { case "0"[[:]] { _vehicle setobjecttexture[0,"\mymodpath\textures\num1.paa"]; }; //etc };

this one below works, and the one above stopped working with 1.63
switch (_number1) do { case 0[[:]] { _vehicle setobjecttexture[0,"\mymodpath\textures\num1.paa"]; }; //etc };
Posted on Nobember 1, 2020 - 10:05 (UTC)
Freddo3000
You are able to call code within the switch statements, such as: _myFunc = { systemChat "0"; case 1: {systemChat "1"}; systemChat "2"; }; _myParameter = 1; switch (_myParameter) do { _myParameter call _myFunc; case 1: {systemChat "4"}; systemChat "3"; default {systemChat "-1";}; }; However the order in which it is executed is difficult to make sense of, see the code comment. This is used by BIS_fnc_missionConversations and BIS_fnc_missionTasks