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| − | {{TOC|side}} {{Table/RVScripting}}
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| − | '''SQF''' stands for '''S'''tatus '''Q'''uo '''F'''unction - a преемник языка [[SQS Syntax|'''S'''tatus '''Q'''uo '''S'''cript]], который устарел с ArmA: Armed Assault, но еще может быть использован в Arma3.
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| − | SQF was first introduced in OFPR together with the [[call]] operator.
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| − | * "Status Quo" кодовое имя Operation_Flashpoint
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| − | * "Combined Arms" кодовое имя ARMA
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| − | * "Futura" кодовое имя ARMA_3.
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| − | Язык SQF довольно прост в своем строении.
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| − | In fact: there are barely any actual language structures at all.
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| − | The functionality is provided via so called ''[[:Category:Scripting_Commands_Arma_3|operators]]'' (or more commonly known [[:Category:Scripting_Commands_Arma_3|scripting commands]]).
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| − | Those [[:Category:Scripting Commands Arma 3|operators]] are one of the following types: [[#Nular Operators|Nular]]{{sic}}, [[#Unary Operators|Unary]], or [[#Binary Operators|Binary]].
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| − | == Terminating an expression ==
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| − | An SQF expression has to be terminated via either {{ic|;}} (preferred by convention!) or {{ic|,}}.
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| − | _num = 10;
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| − | _num = _num + 20; systemChat str _num;
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| − | In the above example, there are three expressions:
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| − | # {{ic|_num {{=}} 10}}
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| − | # {{ic|_num {{=}} _num + 20}}
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| − | # {{ic|[[systemChat]] [[str]] _num}}
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| − | All are separated by {{hl|;}} and not the line return - they could all be inlined and it would not impact the code.
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| − | == Brackets ==
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| − | * {{ic|()}} - Round brackets are used to override the default [[Order of Precedence]] or improve legibility.
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| − | * {{ic|[]}} - Square brackets define [[Array]]s.
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| − | * {{ic|<nowiki>{}</nowiki>}} - Curly brackets enclose instances of the [[Code]] [[:Category:Data Types|Data Type]]. They are also used in [[Control Structures]].
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| − | == Whitespaces ==
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| − | Whitespace consists of tabs and/or space characters.
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| − | For the
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| − | purposes of the
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| − | engine
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| − | The 'line' begins at the first non whitespace character.
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| − | Similarly, trailing whitespace at the end of a line or statement is also ignored.
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| − | == Blank Lines ==
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| − | Blank lines are lines containing nothing but whitespace and are therefore ignored by the engine.
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| − | == Comments ==
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| − | A comment is additional text that gets ignored when a script is parsed.
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| − | They serve as future reference and are often used to explain a specific part of the code.
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| − | In SQF, there are two kind of comments:
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| − | // in-line comment that ends on new line
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| − | /* block comment that can span above multiple lines
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| − | and ends on the following character combination: */
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| − | A comment can occur anywhere but inside a [[String|string]].
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| − | For example, the following would be valid:
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| − | <sqf>1 + /* some random comment in an expression */ 1</sqf>
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| − | It should be mentioned that there is a [[comment]] unary [[:Category:Scripting_Commands_Arma_3|operator]] that should not be used as it will actually be executed (thus taking time to execute) but does nothing besides consuming a [[String|string]].
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| − | There is no benefit in using it and the reason it exists is solely for backward compatibility.
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| − | Another way to make a ''comment'' that way, is to just place a [[String|string]]: {{ic|[...]; "i can be considered as a comment but should not be used"; [...]}}
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| − | ''Comments are removed during the [[PreProcessor_Commands|preprocessing]] phase.'' This is important to know as that prevents usage in e.g a [[String|string]] that gets compiled using the [[compile]] unary [[:Category:Scripting Commands|operator]] or when only using [[loadFile]].
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| − | == Nular Operators ==
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| − | A {{sic|nular}} operator is more or less a computed [[Variables|variable]]. Each time accessed, it will return the current state of something.
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| − | It is tempting to think of a nular{{sic}} [[:Category:Scripting_Commands_Arma_3|operator]] as nothing more but a magic [[Variables|global variable]], but it is important to differentiate!
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| − | Consider following example in a mission with e.g. 5 units:
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| − | // put the result of allUnits into a Variable
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| − | _unitsArray = allUnits;
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| − | // display the current Array size using systemChat
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| − | systemChat str count _unitsArray;
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| − | // create a new unit in the player group
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| − | group player createUnit ["B_RangeMaster_F", getPosATL player, [], 0, "FORM"];
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| − | // output the Array size again
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| − | systemChat str count _unitsArray;
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| − | // output the size of allUnits
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| − | systemChat str count allUnits;
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| − | Now, what would the output of this look like?
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| − | System: 5
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| − | System: 5
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| − | System: 6
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| − | As you can see, {{ic|_unitsArray}} was not automatically updated as it would have been if it was not generated each time. If [[allUnits]] was just a [[Variables|global variable]] with a reference to some internal managed array, our private [[Variables|variable]] should have had reflected the change as [[Data_Types|value types]] are passed by reference.
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| − | The reason for this is because [[allUnits]] and other nular{{sic}} operators just return the current state of something and do not return a reference to eg. an [[Array|array]] containing all units.
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| − | It is generated each time, which is why some of theese operators are more expensive to run then ''just'' using a [[Variables|variable]].
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| − | == Unary Operators ==
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| − | The unary [[:Category:Scripting_Commands_Arma_3|operators]] are [[:Category:Scripting_Commands_Arma_3|operators]] that expect an argument on their right side ({{ic|unary <argument>}}). They always will take the first argument that occurs.
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| − | A common mistake would be the following:
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| − | // create some Array containing three arrays
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| − | _arr = [[1, 2, 3, 4, 5], [1, 2, 3, 4], [1, 2]];
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| − | // wrongly use the select operator to get the count of the third array
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| − | count _arr select 2; // error
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| − | Now, what went wrong?
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| − | Let's put some brackets in the right places to make the mistake understandable:
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| − | (count _arr) select 2; // error
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| − | Due to the nature of unary [[:Category:Scripting_Commands_Arma_3|operators]], count instantly consumes our [[Variables|variable]] ''_arr'' and returns the number ''3''.
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| − | The ''3'' then is passed to [[select]] which does not knows what to do with a number as left argument and thus errors out.
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| − | To do it correctly, one would have to put the {{ic|_arr select 2}} in brackets.
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| − | The correct code thus would be:
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| − | // create an array containing three Arrays
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| − | _arr = [[1, 2, 3, 4, 5], [1, 2, 3, 4], [1, 2]];
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| − | // use brackets to correctly get count of the third Array
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| − | count (_arr select 2); // good :) will evaluate to 2
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| − | == Binary Operators ==
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| − | Binary [[:Category:Scripting_Commands_Arma_3|operators]] expect two arguments ({{ic|<1st argument> binary <2nd argument>}}) and are executed according to their {{HashLink|#precedence}}. If their precedence is equal, they are executed left to right.
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| − | As example, we will look into the following expression:
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| − | <sqf>
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| − | // create a nested Array with 5 levels
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| − | _arr = [[[[[1]]]]];
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| − | // receive the nested number with some random math expressions
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| − | _arr select 0 select 1 - 1 select 15 / 3 - 5 select 0 select 10 * 10 + 4 * 0 - 100 // evaluates to 1
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| − | </sqf>
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| − | Now, let us analyze why this is happening for the first few expressions:
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| − | # _arr is loaded
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| − | # 0 is loaded
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| − | # [[select]] is executed with the result of 1. & 2.
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| − | # 1 is loaded
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| − | # 1 is loaded
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| − | # [[-]] is executed with the result of 4. & 5.
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| − | # [[select]] is executed with the result of 3. & 6.
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| − | # ...
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| − | If we now would put brackets at the correct spots, the expression will get clearer:
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| − | <sqf>((((_arr select 0) select (1 - 1)) select ((15 / 3) - 5)) select 0) select (((10 * 10) + (4 * 0)) - 100)</sqf>
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| − | As you can see the [[a_*_b|*]] and [[a_/_b|/]] are executed first which matches their [[Order of Precedence|precedence]].
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| − | Afterward, the [[+]] and [[-]] [[:Category:Scripting Commands|operators]] will get executed followed by our [[select]] operator, which are executed from the left to the right.
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| − | [[Category: Syntax]]
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