» google_pagerank()
  » preg_replace()
  » imagecreatefrompng()
  » site_pageranks()
  » imagepng()
  » imagedestroy()
  » imagestring()
  » imagecolorallocate()
  » htmlentities()
  » preg_match()
  » fopen()
  » header()
  » getimagesize()
  » preg_match_all()
  » session_start()
  » htmlspecialchars()
  » ob_start()
  » ob_flush()
  » strstr()
  » flush()
  » strpos()
  » setcookie()
  » str_replace()
  » array2vars()
  » nl2br()
  » preg_split()
  » ereg()
  » ereg_replace()
  » urlencode()
  » readgzfile()

Become a sponsor for $15/month. Link is sitewide - PR5 homepage, 20+ PR4 pages, 90+ PR3 pages. Email dave[AT]icemelon[D0T]c0m.

(PHP 4, PHP 5)

is_subclass_of --  Returns TRUE if the object has this class as one of its parents

Description

bool is_subclass_of ( mixed object, string class_name )

This function returns TRUE if the object object , belongs to a class which is a subclass of class_name , FALSE otherwise.

Example 1. is_subclass_of() example

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

// define a child class
class WidgetFactory_Child extends WidgetFactory
{
  var $oink = 'oink';
}

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

if (is_subclass_of($WFC, 'WidgetFactory')) {
  echo "yes, \$WFC is a subclass of WidgetFactory\n";
} else {
  echo "no, \$WFC is not a subclass of WidgetFactory\n";
}


if (is_subclass_of($WF, 'WidgetFactory')) {
  echo "yes, \$WF is a subclass of WidgetFactory\n";
} else {
  echo "no, \$WF is not a subclass of WidgetFactory\n";
}


// usable only since PHP 5.0.3
if (is_subclass_of('WidgetFactory_Child', 'WidgetFactory')) {
  echo "yes, WidgetFactory_Child is a subclass of WidgetFactory\n";
} else {
  echo "no, WidgetFactory_Child is not a subclass of WidgetFactory\n";
}
?>

The above example will output:

yes, $WFC is a subclass of WidgetFactory
no, $WF is not a subclass of WidgetFactory
yes, WidgetFactory_Child is a subclass of WidgetFactory

Related Function(s)

get_class()

get_parent_class()

is_a()