Méthodes magiques
The use of final keyword is just like that occurs in Java
In java final has three uses
1) prevent class Inheritance
2) prevent method overriding or redifination of
method in subclass
3) and to declare constants
But the third point seems to be missing from the PHP
I guess, as i am a java developer Currently gaining competence in PHP
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"
santoshjoshi2003 at yahoo dot co dot in
05-Dec-2008 02:45
05-Dec-2008 02:45
slorenzo at clug dot org dot ve
31-Oct-2007 12:13
31-Oct-2007 12:13
<?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
?>
penartur at yandex dot ru
22-Mar-2007 02:39
22-Mar-2007 02:39
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.