try: Difference between revisions

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m (Text replacement - "<code>([^ ]*)\[\[([a-zA-Z][a-zA-Z0-9_]+)\]\]([^ ]*)<\/code>" to "<code>$1$2$3</code>")
m (Text replacement - "\{\{cc\|([^} ]*)\}\}" to "// $1")
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|x3= <code>[[try]] {
|x3= <code>[[try]] {
[[if]] (a > b) [[throw]] "Error: some error"; {{cc|OK}}
[[if]] (a > b) [[throw]] "Error: some error"; // OK
{{cc|The command argument is static}}
// The command argument is static
} [[catch]] {
} [[catch]] {
[[hint]] [[str]] _exception;
[[hint]] [[str]] _exception;
Line 55: Line 55:
.....
.....
};
};
[[if]] (a > b) [[throw]] ([[call]] _someFunc); {{cc|NOT OK}}
[[if]] (a > b) [[throw]] ([[call]] _someFunc); // NOT OK
{{cc|The command argument is dynamic}}
// The command argument is dynamic
{{cc|_someFunc is called first to get the value regardless of (a > b) outcome}}
// _someFunc is called first to get the value regardless of (a > b) outcome
} [[catch]] {
} [[catch]] {
[[hint]] [[str]] _exception;
[[hint]] [[str]] _exception;
Line 66: Line 66:
.....
.....
};
};
[[if]] (a > b) [[then]] {[[throw]] ([[call]] _someFunc)}; {{cc|OK}}
[[if]] (a > b) [[then]] {[[throw]] ([[call]] _someFunc)}; // OK
{{cc|The command argument is dynamic}}
// The command argument is dynamic
{{cc|_someFunc is only called when (a > b) is [[true]]}}
// _someFunc is only called when (a > b) is [[true]]
} [[catch]] {
} [[catch]] {
[[hint]] [[str]] _exception;
[[hint]] [[str]] _exception;

Revision as of 11:26, 12 May 2022

Hover & click on the images for description

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
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:
123 try {if (_this != 123) throw "invalid argument"} catch {hint str _exception};
Example 3:
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 handling throw catch

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.