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Dan's Study Guide Exams - exceptions

 
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(The following examples are derived from Dan�s Study Guide Exams for chapter 5.)
In the first example, how do you know the compiler will report two errors, instead of stopping after the first one?

In the above example, two compiler error occur
: unreported exception java.lang.ClassNotFoundException;

In the above example, only one compiler error occurs
: unreported exception AException; must be caught or declared to be thrown
although there is potentially another compiler error
: exception BException is never thrown in body of corresponding try statement
 
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marlene ,
in the first example, the case statements fall through (without break) so it throws both the checked exceptions....
 
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For purposes of the exam, you won't have to know how many compiler errors might be thrown on a given piece of code - you will only be required to recognize is any compiler errors will be thrown.
Frankly, I'd say that it's impossible to know how many errors will be thrown without knowing the inner workings of the compiler, which is well beyond the scope of this exam.
Corey
 
preeti khane
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Marlene,
In the first example...let me clarify.. at compile time all uncaught checked exceptions will be reported as compile errors
 
preeti khane
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marlene,
In the 2nd example the compiler reports uncaught exception because method m() does not explicitly throw AException.... Hence the compile error
If u changed m() to m() throws AException{...} it will compile fine..

The compiler needs to check and be sure that checked exceptions are caught or declared to be thrown... (the only exclusion to this rule is RuntimeException or Errors)... As long as this rule is adhered to it has no problem....
 
Marlene Miller
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Thank you Preeti and Corey.
 
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It seems that the compiler knows the class hierarchy. In other words, if you modify the code in m() to throw BException and catch AException, then the code compile fine without errors.
 
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