在PHP中尝试/捕获块不捕获异常

Question

I am trying to run this Example #1 from this page: http://php.net/manual/en/language.exceptions.php

<?php
function inverse($x) {
    if (!$x) {
        throw new Exception('Division by zero.');
    }
    return 1/$x;
}
try {
    echo inverse(5) . "
";
    echo inverse(0) . "
";
} catch (Exception $e) {
    echo 'Caught exception: ',  $e->getMessage(), "
";
}
// Continue execution
echo "Hello World
";
?>

However instead of the desired output I get:

0.2
Fatal error: Uncaught exception 'Exception' with message 'Division by zero.' 
in xxx:
7 Stack trace: #0 xxx(14): inverse(0) #1 {main} thrown in xxx on line 7

The developer environment I am using is UniServer 3.5 with PHP 5.2.3

Answer 1

My initial though is you have a typo in the name of the exception you are catching/throwing, but if your code is exactly the same I'm not sure exactly what is going on.

Try the following modification of the original script, and paste your results. It will help diagnose your issue a bit better.

<?php

//set up exception handler to report what we didn't catch
function exception_handler($exception) {

    if($exception instanceof MyException) {
        echo "you didn't catch a myexception instance
";

    } else if($exception instanceof Exception) {
        echo "you didn't catch a exception instance
";

    } else {
        echo "uncaught exception of type: ".gettype($exception)."
";
    }

    echo "Uncaught exception: " , $exception->getMessage(), "
";
}

//install the handler
set_exception_handler('exception_handler');

class MyException extends Exception {
}

function inverse($x) {
    if (!$x) {
        throw new MyException('Division by zero.');
    }
    else return 1/$x;
}

try {
    echo inverse(5) . "
";
    echo inverse(0) . "
";
} catch (MyException $e) {
    echo 'Caught myexception: ',  $e->getMessage(), "
";
} catch (Exception $e) {
    echo 'Caught exception: ',  $e->getMessage(), "
";
}

// Continue execution
echo 'Hello World';
?>