An output of the entire inheritance chain using closures, recursion, and OOP
class ParentClass {
public static function getChain() {
$chain = null;
return $function = function($className='') use (& $chain, & $function) {
if (empty($className))
$className = static::class;
if (empty($chain))
$chain = $className;
$parent = get_parent_class($className);
if ($parent !== false) {
$chain .= " > {$parent}";
return $function($parent);
}
return $chain;
};
}
}
class Child extends ParentClass {}
class SubChild extends Child {}
class Sub2 extends SubChild {}
class Sub3 extends Sub2 {}
class Sub4 extends Sub3 {}
class Sub5 extends Sub4 {}
class Sub6 extends Sub5 {}
class Sub7 extends Sub6 {}
printf("%s\n", Sub7::getChain()());
$getChain = Sub7::getChain();
printf("%s\n", $getChain('Sub3'));
Output is:
Sub7 > Sub6 > Sub5 > Sub4 > Sub3 > Sub2 > SubChild > Child > ParentClass
Sub3 > Sub2 > SubChild > Child > ParentClass
get_parent_class
(PHP 4, PHP 5, PHP 7, PHP 8)
get_parent_class — Gibt den Namen der Elternklasse eines Objektes zurück
Beschreibung
Gibt den Namen der Elternklasse eines Objekts oder einer Klasse zurück.
Parameter-Liste
-
object_or_class -
Der Name des zu untersuchenden Objekts oder der Klasse.
Rückgabewerte
Gibt den Namen der Elternklasse der Klasse zurück, von der
object_or_class eine Instanz oder der Name ist.
Falls das Objekt keine Elternklasse hat oder die angegebene Klasse nicht
existiert, wird false zurückgegeben.
Changelog
| Version | Beschreibung |
|---|---|
| 8.3.0 |
Wenn get_parent_class() ohne Argument aufgerufen
wird, führt dies nun zu einer E_DEPRECATED-Warnung;
zuvor gab diese Funktion, wenn sie innerhalb einer Klasse aufgerufen
wurde, den Namen dieser Klasse zurück.
|
| 8.0.0 |
Der Parameter object_or_class akzeptiert jetzt
nur noch Objekte oder gültige Klassennamen.
|
Beispiele
Beispiel #1 Die Verwendung von get_parent_class()
<?php
class Vater {
function __construct()
{
// implementiert etwas Logik
}
}
class Kind extends Vater {
function __construct()
{
echo "Ich bin das Kind von " , get_parent_class($this) , "\n";
}
}
class Kind2 extends Vater {
function __construct()
{
echo "Ich bin ebenfalls das Kind von " , get_parent_class('kind2') , "\n";
}
}
$foo = new kind();
$bar = new kind2();
?>Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Ich bin das Kind von Vater Ich bin ebenfalls das Kind von Vater
Siehe auch
- get_class() - Ermittelt den Klassennamen eines Objekts
- is_subclass_of() - Prüft ob ein Objekt von der angegebenen Klasse abstammt oder sie implementiert
- class_parents() - Return the parent classes of the given class
add a note
User Contributed Notes 7 notes
yukal dot alexander at gmail dot com ¶
6 years ago
matt-php at DONT-SPAM-ME dot bitdifferent dot com ¶
20 years ago
PHP (4 at least, dunno about 5) stores classnames in lower case, so:
<?PHP
class Foo
{
}
class Bar extends Foo
{
}
echo get_parent_class('Bar');
echo "\n";
echo get_parent_class('bar');
?>
will output:
foo
foo
falundir at gmail dot com ¶
12 years ago
You can use this function to find common parent of multiple objects or classes.
<?php
/**
* Returns name of the first (in class hierarchy) common parent class of all provided objects or classes.
* Returns FALSE when common class is not found.
*
* @param mixed $objects Array that can contain objects or class names.
* @return mixed
*/
function get_first_common_parent($objects) {
$common_ancestors = null;
foreach($objects as $object) {
if (is_object($object)) {
$class_name = get_class($object);
} else {
$class_name = $object;
}
$parent_class_names = array();
$parent_class_name = $class_name;
do {
$parent_class_names[] = $parent_class_name;
} while($parent_class_name = get_parent_class($parent_class_name));
if ($common_ancestors === null) {
$common_ancestors = $parent_class_names;
} else {
$common_ancestors = array_intersect($common_ancestors, $parent_class_names);
}
}
return reset($common_ancestors);
}
?>
Example:
<?php
class A {
}
class B extends A {
}
class D extends B {
}
class E extends B {
}
class C extends A {
}
class F extends C {
}
class G extends F {
}
class H {
}
//returns "A"
get_first_common_parent(array('G', 'E'));
//returns "F"
get_first_common_parent(array(new G(), 'F'));
//returns false (no common parent)
get_first_common_parent(array('C', 'H'));
//returns false (non-existent class provided)
get_first_common_parent(array(new B(), 'X'));
?>
levu ¶
13 years ago
I wrote a simple function doing the reverse thing: get the children:
<?php
function get_child($instance, $classname) {
$class = $classname;
$t = get_class($instance);
while (($p = get_parent_class($t)) !== false) {
if ($p == $class) {
return $t;
}
$t = $p;
}
return false;
}
abstract class A {
function someFunction() {
return get_child($this, __CLASS__);
}
}
class B extends A {
}
class C extends B {
}
$c = new C();
echo $c->someFunction(); //displays B
?>
jake at qzdesign dot co dot uk ¶
5 years ago
Note that from PHP 5.5 you can also use `parent::class` from within a method, e.g.
<?php
function child()
{
echo "I'm ", parent::class, "'s son\n";
}
?>
Looks a bit tidier and technically probably more optimal, as it avoids a function call lookup.
ssb45 at cornell dot edu ¶
16 years ago
"'If called without parameter outside object' What on earth does that mean?"
There are two places this could be called:
1. From within a member function of an object. In this case, it may be called with no parameters and will return the parent class of the object owning the member function. (If the parameter is included, then it will return the parent class of the specified class as normal.)
2. From outside an object (i.e., global or function scope). In this case, PHP doesn't know what class you're talking about if you don't include a parameter, so it returns FALSE. (But, of course, it works if you specify the class with the parameter.)
radu dot rendec at ines dot ro ¶
20 years ago
If the argument obj is a string and the class is not defined, then the function returns FALSE.
If the argument obj is an object created from a class with no ancestors (or a string representing a class with no ancestors), then the function returns FALSE.
