is_a

(PHP 4 >= 4.2.0, PHP 5)

is_a — 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