PHP 5 has an exception model similar to that of other programming languages.
An exception can be thrown, and caught ("catched") within PHP.
Code may be surrounded in a try block, to facilitate the catching of potential
exceptions. Each try must have at least one corresponding catch block.
Multiple catch blocks can be used to catch different classes of exeptions.
Normal execution (when no exception is thrown within the try block, or when a
catch matching the thrown exception's class is not present) will continue after
that last catch block defined in sequence. Exceptions can be thrown (or re-thrown)
within a catch block.
When an exception is thrown, code following the statement will not be executed, and
PHP will attempt to find the first matching catch block. If an exception is not caught,
a PHP Fatal Error will be issued with an "Uncaught Exception ..." message, unless a
handler has been defined with set_exception_handler().
Note: Internal PHP functions mainly use Error reporting, only modern Object oriented
extensions use exceptions. However, errors can be simply translated to exceptions with
ErrorException.
Tip:
The Standard PHP Library (SPL) provides a good number of built-in exceptions.
Example: Throwing an Exception
function inverse($x) {
if (!$x) {
throw new Exception('Division by zero.');
}
else return 1/$x;
}
try {
echo inverse(5) . "\n";
echo inverse(0) . "\n";
} catch (Exception $e) {
echo 'Caught exception: ', $e->getMessage(), "\n";
}
// Continue execution
echo 'Hello World';
?>
The above example will output:
0.2
Caught exception: Division by zero.
Hello World
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