Possible Duplicate: What are the PHP operators “?” and “:” called and what do they do?
From http://twitto.org/
<?PHP
require __DIR__.'/c.php';
if (!is_callable($c = @$_GET['c'] ?: function() { echo 'Woah!'; }))
throw new Exception('Error');
$c();
?>
Twitto uses several new features available as of PHP 5.3:
What does number 2 do with the ?: in PHP 5.3?
Also, what do they mean by anonymous functions? Wasn't that something that has existed for a while?
?:
is a form of the conditional operator which was previously available only as:
expr ? val_if_true : val_if_false
In 5.3 it's possible to leave out the middle part, e.g. expr ?: val_if_false
which is equivalent to:
expr ? expr : val_if_false
From the manual:
Since PHP 5.3, it is possible to leave out the middle part of the conditional operator. Expression
expr1 ?: expr3
returnsexpr1
ifexpr1
evaluates toTRUE
, andexpr3
otherwise.