PHP. Руководство по PHP. 2005
Exceptions
Глава 20. Exceptions
Содержание
PHP 5 has an exception model similar to that of other programming languages. An exception can be thrown, try and caught within PHP. A Try block must include at least one catch block. Multiple catch blocks can be used to catch different classtypes; execution will continue after that last catch block defined in sequence. Exceptions can be thrown within catch blocks.
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 there has been a handler defined with set_exception_handler().
Extending Exceptions
A User defined Exception class can be defined by extending the built-in Exception class. The members and properties below, show what is accessible within the child class that derives from the built-in Exception class.
Пример 20-2. The Built in Exception class
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If a class extends the built-in Exception class and re-defines the constructor, it is highly recomended that it also call parent::__construct() to ensure all available data has been properly assigned. The __toString() method can be overriden to provide a custom output when the object is presented as a string.
Пример 20-3. Extending the Exception class
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Type Hinting
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