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|version1= 1.00 | |version1= 1.00 | ||
|gr1= Program Flow | |gr1= Program Flow | ||
|descr= Defines a try-catch structure. This sets up an [[Exception handling|exception handling]] block. Any thrown exception in a try block is caught in a [[catch]] block. The structured exception block has the following form: | |descr= Defines a try-catch structure. This sets up an [[Exception handling|exception handling]] block. Any thrown exception in a try block is caught in a [[catch]] block. The structured exception block has the following form: | ||
| Line 11: | Line 11: | ||
{ {{codecomment|/* block that can throw exception */}} } | { {{codecomment|/* block that can throw exception */}} } | ||
[[catch]] | [[catch]] | ||
{ {{codecomment|/* block that processes the exception. Exception is described in the ''_exception'' variable */}} };</code> | { {{codecomment|/* block that processes the exception. Exception is described in the ''_exception'' variable */}} };</code> | ||
|s1= [[try]] code | |s1= [[try]] code | ||
|p1= code: [[Code]] | |p1= code: [[Code]] | ||
|r1= [[Exception handling|Exception Type]] | |r1= [[Exception handling|Exception Type]] | ||
| s2= args [[try]] code {{Since|arma3|1.53.133045|y}} | | s2= args [[try]] code {{Since|arma3|1.53.133045|y}} | ||
|p21= args: [[Anything]] - passed arguments, will be put in ''_this'' variable inside the "code" |PARAMETER21= | |p21= args: [[Anything]] - passed arguments, will be put in ''_this'' variable inside the "code" |PARAMETER21= | ||
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|p22= code: [[Code]] |PARAMETER22= | |p22= code: [[Code]] |PARAMETER22= | ||
| r2= [[Exception handling|Exception Type]] | | r2= [[Exception handling|Exception Type]] | ||
|x1= <code>[[try]] {[[throw]] "invalid argument"} [[catch]] {[[hint]] [[str]] _exception};</code> | |x1= <code>[[try]] {[[throw]] "invalid argument"} [[catch]] {[[hint]] [[str]] _exception};</code> | ||
|x2= {{Since|arma3|1.53.133045}}: <code>123 [[try]] {[[if]] (_this != 123) [[throw]] "invalid argument"} [[catch]] {[[hint]] [[str]] _exception};</code> | |x2= {{Since|arma3|1.53.133045}}: <code>123 [[try]] {[[if]] (_this != 123) [[throw]] "invalid argument"} [[catch]] {[[hint]] [[str]] _exception};</code> | ||
|x3= The correct usage of shorthand alt syntax: <code>[[try]] { | |x3= The correct usage of shorthand alt syntax: <code>[[try]] { | ||
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} [[catch]] { | } [[catch]] { | ||
[[hint]] [[str]] _exception; | [[hint]] [[str]] _exception; | ||
};</code> | };</code> | ||
|seealso= [[Exception handling]], [[throw]], [[catch]] | |seealso= [[Exception handling]], [[throw]], [[catch]] | ||
Revision as of 11:24, 18 January 2021
Description
- Description:
- Defines a try-catch structure. This sets up an exception handling block. Any thrown exception in a try block is caught in a catch block. The structured exception block has the following form:
try { /* block that can throw exception */ } catch { /* block that processes the exception. Exception is described in the _exception variable */ }; - Groups:
- Program Flow
Syntax
- Syntax:
- try code
- Parameters:
- code: Code
- Return Value:
- Exception Type
Alternative Syntax
- Syntax:
- args try code Template:Since
- Parameters:
- args: Anything - passed arguments, will be put in _this variable inside the "code"
- code: Code
- Return Value:
- Exception Type
Examples
- Example 1:
try {throw "invalid argument"} catch {hint str _exception};- Example 2:
- Template:Since:
123 try {if (_this != 123) throw "invalid argument"} catch {hint str _exception}; - Example 3:
- The correct usage of shorthand alt syntax:
try { if (a > b) throw "Error: some error"; // OK // The command argument is static } catch { hint str _exception; }; try { _someFunc = { ..... }; if (a > b) throw (call _someFunc); // NOT OK // The command argument is dynamic // _someFunc is called first to get the value regardless of (a > b) outcome } catch { hint str _exception; }; try { _someFunc = { ..... }; if (a > b) then {throw (call _someFunc)}; /// OK // The command argument is dynamic // _someFunc is only called when (a > b) is true } catch { hint str _exception; };
Additional Information
- See also:
- Exception handlingthrowcatch
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
- Posted on June 9, 2015 - 20:52 (UTC)
- Killzone Kid
- Do not expect this behave like Javascript try catch and ignore all errors. But it does have one useful behaviour. Normally when a runtime error occurs in SQF (unlike when there is compile error) it continues to execute till the end. But if the script is placed in try {} scope and throw is used upon error, the script immediately terminates, exits the try {} scope and enters catch {} scope. This way it is possible to process possible exceptions in civilised manner.