Méthodes magiques
<?php
class parentClass {
public function someMethod() { }
}
class childClass extends parentClass {
public final function someMethod() { } //override parent function
}
$class = new childClass;
$class->someMethod(); //call the override function in chield class
?>
Mot-clé "final"
PHP 5 introduit le mot-clé "final" qui empêche les classes filles de surcharger une méthode en en préfixant la définition par le mot-clé "final". Si la classe elle-même est définie comme finale, elle ne pourra pas être étendue.
Exemple #1 Exemple de méthode finale
<?php
class BaseClass {
public function test() {
echo "BaseClass::test() appelé\n";
}
final public function moreTesting() {
echo "BaseClass::moreTesting() appelé\n";
}
}
class ChildClass extends BaseClass {
public function moreTesting() {
echo "ChildClass::moreTesting() appelé\n";
}
}
// Résultat : Fatal error: Cannot override final method BaseClass::moreTesting()
?>
Exemple #2 Exemple de classe finale
<?php
final class BaseClass {
public function test() {
echo "BaseClass::test() appelé\n";
}
// Ici, peut importe si vous spécifiez la fonction en finale ou pas
final public function moreTesting() {
echo "BaseClass::moreTesting() appelé\n";
}
}
class ChildClass extends BaseClass {
}
// Résultat : Fatal error: Class ChildClass may not inherit from final class (BaseClass)
?>
add a note
User Contributed NotesMot-clé "final"
slorenzo at clug dot org dot ve
31-Oct-2007 08:13
31-Oct-2007 08:13
penartur at yandex dot ru
22-Mar-2007 10:39
22-Mar-2007 10:39
Note that you cannot ovverride final methods even if they are defined as private in parent class.
Thus, the following example:
<?php
class parentClass {
final private function someMethod() { }
}
class childClass extends parentClass {
private function someMethod() { }
}
?>
dies with error "Fatal error: Cannot override final method parentClass::someMethod() in ***.php on line 7"
Such behaviour looks slight unexpected because in child class we cannot know, which private methods exists in a parent class and vice versa.
So, remember that if you defined a private final method, you cannot place method with the same name in child class.