Tag Archives: Throw

Exception Handling

Exception handling is used to change the normal flow of the code execution if a specified error (exceptional) condition occurs. This condition is called an exception.

Exceptions or errors (more on that see below) end code execution, unless they are handled with try-catch.

try {
// code that throws an Exception
} catch (Exception $ex) {
// Exception is handled, code
continues
}

Several catch statements may be used to differentiate between several kinds of exceptions and errors.

try {
// code that throws an Exception
} catch (CustomExceptionClass $ex) {
// custom Exception is handled
} catch (Exception $ex) {
// Exception is handled
} catch (Error $err) {
// Error is handled
}

Several errors may be handled with the same code.

try {
// code that throws an Exception
} catch (Exception | CustomException $ex)
{
// custom Exception and Exception
}

Optional finally block contains code that runs after the trycatch block, no matter whether an error was caught or not

This is what normally happens when an exception is triggered:

  • The current code state is saved
  • The code execution will switch to a predefined (custom) exception handler function
  • Depending on the situation, the handler may then resume the execution from the saved code state, terminate the script execution or continue the script from a different location in the code