is_subclass_of

说明

is_subclass_of() 例子

is_subclass_of

(PHP 4, PHP 5)

is_subclass_of -- 如果此对象是该类的子类，则返回 TRUE

说明

bool is_subclass_of ( object object, string class_name )

如果对象 object 所属类是类 class_name 的子类，则返回 TRUE，否则返回 FALSE。

注: 自 PHP 5.0.3 起也可以用一个字符串来指定 object 参数（类名）。

is_subclass_of() 例子

<?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\";

} else {

echo "no, \\$WFC is not a subclass of WidgetFactory\";

}

if (is_subclass_of($WF, 'WidgetFactory')) {

echo "yes, \\$WF is a subclass of WidgetFactory\";

} else {

echo "no, \\$WF is not a subclass of WidgetFactory\";

}

// usable only since PHP 5.0.3

if (is_subclass_of('WidgetFactory_Child', 'WidgetFactory')) {

echo "yes, WidgetFactory_Child is a subclass of WidgetFactory\";

} else {

echo "no, WidgetFactory_Child is not a subclass of WidgetFactory\";

}

?>

输出：

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