Throw And Catch Exception

try {
      validateInput(0);
} catch (Exception $ex) {
      echo "Error" . $ex->getMessage();
}

function validateInput($input) {
      if ($input <= 0) {
            throw new Exception("Invalid input");
      }
}

Throwing A Custom Exception

set_exception_handler ('exceptionHandler'); // on any exception go to this specific (our custom) method.
throw new Exception("An error occurred");

function exceptionHandler($ex) {
      echo "Custom Exception Handler: " . $ex->getMessage();
}

Handling Multiple Exceptions

set_exception_handler ('exceptionHandler'); // on any exception go to this specific (our custom) method.
multipleExceptions();

function multipleExceptions() {
      try {
            throw new Exception("Exception - 1");
      } catch (Exception $ex) {
            throw $new Exception("Exception - 2" . $ex->getMessage());
      }
}
function exceptionHandler($ex) {
      echo "Custom Exception Handler: " . $ex->getMessage();
}

Finally Block

try {
      throw new Exception("Exception - 1");
} catch (Exception $ex) {
      throw $new Exception("Exception - 2" . $ex->getMessage());
} finally {
      echo "finally block executes anyway";
}

Raise And Handle Error

set_error_handler ('errorHandler'); // on any error go to this specific (our custom) method.
echo (1 / 0); // raise an error

function errorHandler ($errorNumber, $errorMessage) {
      echo "Custom Error Handler: " . "Error #: " . $errorNumber . " Error Message: " . $errorMessage;
}