PHP-Handbuch: Checks if the object is of this class or has this class as one of its parents

Beschreibung

bool is_a ( object $object , string $class_name [, bool $allow_string = FALSE ] )

Checks if the given object is of this class or has this class as one of its parents.

Parameter-Liste

object: The tested object
class_name: The class name
allow_string: If this parameter set to FALSE, string class name as object is not allowed. This also prevents from calling autoloader if the class doesn't exist.

Rückgabewerte

Returns TRUE if the object is of this class or has this class as one of its parents, FALSE otherwise.

Changelog

Version	Beschreibung
5.3.9	Added `allow_string` parameter
5.3.0	This function is no longer deprecated, and will therefore no longer throw `E_STRICT` warnings.
5.0.0	This function became deprecated in favour of the instanceof operator. Calling this function will result in an `E_STRICT` warning.

Beispiele

Beispiel #1 is_a example


<?php
// define a class
class WidgetFactory
{
  var $oink = 'moo';
}

// create a new object
$WF = new WidgetFactory();

if (is_a($WF, 'WidgetFactory')) {
  echo "yes, \$WF is still a WidgetFactory\n";
}
?>

Beispiel #2 Using the instanceof operator in PHP 5


<?php
if ($WF instanceof WidgetFactory) {
    echo 'Yes, $WF is a WidgetFactory';
}
?>

Siehe auch

get_class
get_parent_class
is_subclass_of