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== Why is this an issue?
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Exceptions handlers (``++catch++``) are evaluated in the order they are written. Once a match is found, the evaluation stops.
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In some contexts a ``++catch++`` block is dead code as it will never catch any exception:
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* If there is a handler for a base class followed by a handler for class derived from that base class, the second handler will never trigger: the handler for the base class will match the derived class, and will be the only executed handler.
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* When multiple ``++catch++`` blocks try to catch the same exception class, only the first one will be executed.
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This rule raises an issue when a ``++catch++`` block catches every exception before a later ``++catch++`` block could catch it.
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=== Noncompliant code example
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[source,php]
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----
class MyException extends Exception {}
class MySubException extends MyException {}
try {
doSomething();
} catch (MyException $e) {
echo $e;
} catch (MySubException $e) { // Noncompliant: MySubException is a subclass of MyException
echo "Never executed";
}
----
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=== Compliant solution
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[source,php]
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----
class MyException extends Exception {}
class MySubException extends MyException {}
try {
doSomething();
} catch (MySubException $e) {
echo "Executed";
} catch (MyException $e) {
echo $e;
}
----
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ifdef::env-github,rspecator-view[]
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'''
== Implementation Specification
(visible only on this page)
include::../highlighting.adoc[]
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'''
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== Comments And Links
(visible only on this page)
include::../comments-and-links.adoc[]
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endif::env-github,rspecator-view[]