Métodos mágicos
<?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
?>
La palabra reservada 'Final'
PHP 5 introduce la palabra reservada 'final', la cual prevee que las clases hijo puedan sobreescribir un método, usando el prefijo 'final' en la definición del método. Si la clase en sí misma es definida como 'final' entonces no puede ser extendida.
Example #1 Ejemplo de métodos con Final
<?php
class BaseClass {
public function test() {
echo "BaseClass::test() called\n";
}
final public function moreTesting() {
echo "BaseClass::moreTesting() called\n";
}
}
class ChildClass extends BaseClass {
public function moreTesting() {
echo "ChildClass::moreTesting() called\n";
}
}
// Results in Fatal error: Cannot override final method BaseClass::moreTesting()
?>
Example #2 Ejemplo de clase con Final
<?php
final class BaseClass {
public function test() {
echo "BaseClass::test() called\n";
}
// Here it doesn't matter if you specify the function as final or not
final public function moreTesting() {
echo "BaseClass::moreTesting() called\n";
}
}
class ChildClass extends BaseClass {
}
// Results in Fatal error: Class ChildClass may not inherit from final class (BaseClass)
?>
add a note
User Contributed NotesLa palabra reservada '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.