ฟังก์ชั่น is_subclass_of()
ความหมายของฟังก์ชั่นและการใช้งาน
การตรวจสอบว่า object มีคลาส parents อยู่หรือไม่ ด้วยฟังก์ชั่น is_subclass_of()
รูปแบบการเขียน (Syntax)
bool is_subclass_of ( mixed $object , string $class_name [, bool $allow_string = TRUE ] )
ตัวอย่างที่ 1
<?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";
}
?>
Output
yes, $WFC is a subclass of WidgetFactory
no, $WF is not a subclass of WidgetFactory
yes, WidgetFactory_Child is a subclass of WidgetFactory
ตัวอย่างที่ 2
<?php
// Define the Interface
interface MyInterface
{
public function MyFunction();
}
// Define the class implementation of the interface
class MyClass implements MyInterface
{
public function MyFunction()
{
return "MyClass Implements MyInterface!";
}
}
// Instantiate the object
$my_object = new MyClass;
// Works since 5.3.7
// Test using the object instance of the class
if (is_subclass_of($my_object, 'MyInterface')) {
echo "Yes, \$my_object is a subclass of MyInterface\n";
} else {
echo "No, \$my_object is not a subclass of MyInterface\n";
}
// Test using a string of the class name
if (is_subclass_of('MyClass', 'MyInterface')) {
echo "Yes, MyClass is a subclass of MyInterface\n";
} else {
echo "No, MyClass is not a subclass of MyInterface\n";
}
?>
Output
Yes, $my_object is a subclass of MyInterface
Yes, MyClass is a subclass of MyInterface