Pro PHP- Patterns, Frameworks, Testing and More

(^194) CHAPTER 13 ■ SPL EXCEPTIONS
Fatal error: Uncaught exception 'RangeException' with message
'The sensor broke down.' in listing6.php:14
Stack trace:
#0 listing6.php(19): Monitor::watch()
#1 {main}
thrown in listing6.php on line 14

Invalid Argument Exceptions

The InvalidArgumentException exception is designed to be thrown when a function or method

receives an argument that is invalid.

class InvalidArgumentException extends LogicException

This is distinct from a DomainException in that it does not deal with a set of values, but

instead involves the mixing of incompatible types. For example, when calling a function that

expects an integer, passing a string might be considered an invalid argument. Listing 13-7

demonstrates using InvalidArgumentException.

Listing 13-7. Using InvalidArgumentException

function sum($a, $b) {

if(!is_numeric($a) || !is_numeric($b)) {

throw new InvalidArgumentException("Invalid Argument");

}

return ($a+$b);

}

echo sum(1,2);

echo sum('a','b');

3

Fatal error: Uncaught exception 'InvalidArgumentException'

with message 'Invalid Argument' in listing7.php:6

Stack trace:

#0 listing7.php(12): sum('a', 'b')

#1 {main}

thrown in listing7.php on line 6

Length Exceptions

LengthException should be thrown whenever a problem with length occurs.

class LengthException extends LogicException

McArthur_819-9C13.fm Page 194 Thursday, February 28, 2008 7:53 AM