I am Studying about Exceptions At W3schools At this Link, inside the link just before the heading:
"Re-throwing Exceptions"
there is a sentence that say:
"If the exception thrown were of the class customException and there were no customException catch, only the base exception catch, the exception would be handled there."
If can someone please give me an example for this sentence i will be very thankful.
Basically they're saying if you don't have a catch statement set up to catch customException it will fall through to the general Exception catch statement.
In this example, the first catch statement will catch customException because it explicitly is designed to do so.
try {
// fail
throw new customException();
}
catch (customException $e) {
// catch custom exception
}
catch (Exception $e) {
// catch any uncaught exceptions
}
In the next example, because that clause it missing the generic Exception catch block will catch it instead:
try {
// fail
throw new customException();
}
catch (Exception $e) {
// catch any uncaught exceptions
}
Take a look at Example #2 on this page of the PHP manual
And w3schools isn't the best place to learn PHP, it's (in)famous for its errors
Say you have a custom exception defined as
class CustomException extends Exception.
Now somewhere in your code:
try
{
// do something that throws a CustomException
}
catch(Exception $e) // you are only catching Exception not CustomException,
// because there isn't a specific catch block for CustomException, and
// because Exception is a supertype of CustomException, the exception will
// still be caught here.
{
echo 'Message: ' .$e->getMessage();
}
So what it means is that because CustomException is a subclass of Exception, as long as you catch the Exception type of the superclass without a catch block for the more specific sub class type, it will still be caught
There are two catch blocks in the example. The first catches only customException; the next one catches any Exception. If the first block catches anything, you never get to the second block. But since a customException is also an example of an Exception, it would have gotten caught there if we didn't have the first catch block. This way, the first catch catches it, and the execution never reaches the second.
In the meantime, read the link I posted above, and why w3schools is a bad idea.
