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43. Advanced Error Handling & Custom Exceptions

Building robust error hierarchies.

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Applications benefit from custom exception classes that extend Exception (or a domain-specific base exception) to represent distinct failure modes, such as ValidationException or InsufficientFundsException, allowing callers to catch precisely what they can handle. set_exception_handler() and set_error_handler() let you centralize handling of uncaught exceptions and legacy-style errors, respectively.

Since PHP 7, most fatal errors are represented as Error objects implementing Throwable, meaning a single catch (\Throwable $e) block can capture both traditional exceptions and previously uncatchable engine errors like TypeError.

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Check your understanding

1. Why create custom exception subclasses like ValidationException?
To make code slowerTo let callers catch specific failure types preciselyPHP requires itTo avoid using try/catch
2. What can catch(\Throwable $e) capture that catch(\Exception $e) cannot?
Nothing extraEngine Error objects like TypeErrorOnly warningsDatabase errors

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