ZEND PHP 5 Certification STUDY GUIDE

130 ” Object Oriented Programming in PHP
Throwing Exceptions
Exceptions are usually created and thrown when an error occurs by using the throw
construct:
i
Although it is common practice to do so, you don’t need to create the Exception object
directly in the throw expression.
if ($error) {
throw new Exception ("This is my error");
}
Exceptions then “bubble up” until they are either handled by the script or cause a
fatal exception. The handling of exceptions is performed using a try...catch block:
try {
if ($error) {
throw new Exception ("This is my error");
}
} catch (Exception $e) {
// Handle exception
}
In the example above, any exception that is thrown inside the try{} block is going to
be caught and passed on the code inside the catch{} block, where it can be handled
as you see fit.
Note how the catch() portion of the statement requires us to hint the type of Exception
that we want to catch; one of the best features of exceptions is the fact that
you can decide which kind of exception to trap. Since you are free to extend the base
Exception class, this means that different nested try..catch blocks can be used to
trap and deal with different types of errors:
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class myException extends Exception { }
try {
try {