PHP Throwable vs Exception

In PHP, Throwable and Exception are related concepts but with slightly different behaviors and use cases.

Throwable

Throwable is a base interface implemented by both Exception and Error in PHP. It represents any object that can be thrown using the throw statement. It is the top level of the throwable hierarchy.

Exception

Exception is a class that is used to represent exceptional conditions that occur during the execution of a PHP script. It is the most commonly used class for error handling and can be extended to create custom exception classes.

Creating an Exception

To create a new exception, you can extend the Exception class and add any additional methods or properties you need. For example:

class CustomException extends Exception {
    // Additional methods or properties
}

Throwing an Exception

Exceptions can be thrown using the throw statement. This will generate a backtrace of the code and halt the normal execution flow.

throw new CustomException('A custom exception occurred.');

Catching an Exception

Exceptions can be caught using the try and catch blocks. This allows you to handle the exception and take any necessary actions.

try {
    // Code that may throw an exception
} catch (CustomException $e) {
    // Handle the exception
    echo 'Caught custom exception: ' . $e->getMessage();
} catch (Exception $e) {
    // Catch all other exceptions
    echo 'Caught other exception: ' . $e->getMessage();
}

Comparison

While both Throwable and Exception are used for error handling, there are some key differences:

• Throwable is the base interface that can represent both exceptions and errors, whereas Exception is a class specifically designed for exceptions.
• Throwable allows catching both exceptions and errors, providing a unified approach to handling different types of errors.
• Throwable includes the getPrevious() method, which returns the previous throwable (either an exception or an error) that caused the current throwable to be thrown.
• Throwable can be caught by using the catch block without specifying a specific throwable type.
• Exception is commonly used for custom exception classes, as it provides additional methods and properties specifically for exception handling.

It is generally recommended to catch and handle exceptions specifically using the Exception class, while using Throwable may be useful for generic error handling or logging.

Marking code blocks as follows:

```php
// PHP code here