Exemples
Overloading is defining a method multiple times with different input parameters, then conditionally running whichever method matches the provided input.
It looks like the "overload" function just enables magic methods for a class, which can be used in implementing an extremely janky simulation of overloading.
Also, it seems that magic methods are enabled by default in php5 regardless of whether the overload function has been run on a class.
Voici un exemple simple de fonctions utilisant overload() :
Exemple #1 Overload avec une classe PHP
<?php
class OO {
var $a = 111;
var $elem = array('b' => 9, 'c' => 42);
// Fonction de callback pour la lecture de membre
function __get($prop_name, &$prop_value)
{
if (isset($this->elem[$prop_name])) {
$prop_value = $this->elem[$prop_name];
return true;
} else {
return false;
}
}
// Fonction de callback pour l'écriture de membre
function __set($prop_name, $prop_value)
{
$this->elem[$prop_name] = $prop_value;
return true;
}
}
// Ici, l'initiation de l'overload
overload('OO');
$o = new OO;
echo "\$o->a: $o->a\n"; // print: $o->a: 111
echo "\$o->b: $o->b\n"; // print: $o->b: 9
echo "\$o->c: $o->c\n"; // print: $o->c: 42
echo "\$o->d: $o->d\n"; // print: $o->d:
// ajout d'une nouvelle valeur au membre $elem, en programmation OOP
$o->x = 56;
// instantiation de la classe stdclass (elle existe par défaut en PHP 4)
// $val n'est pas surchargée !
$val = new stdclass;
$val->prop = 555;
// Forcez "a" à être un tableau avec l'élément $val
// Mais _set() forcera cet élément dans le tableau $elem
$o->a = array($val);
var_dump($o->a[0]->prop);
?>
add a note
User Contributed NotesOverload avec une classe PHP
scurvysquid at yahoo dot com
04-Jun-2009 02:43
04-Jun-2009 02:43
Anonymous
26-Mar-2009 07:48
26-Mar-2009 07:48
You can't redeclare because PHP won't know which one to use. Use a default value and test conditionally instead such as
<?php
public function method($arg=false){
if($arg==false){
//do something
} else {
//do something else
}
}
?>
ly dot sitthykun at yahoo dot com
22-Jan-2009 05:47
22-Jan-2009 05:47
<?php
class Foo{
public function method(){
echo "call Method no paramater";
}
public function method($par){
echo "call Method has a paramater";
}
}
$foo = new Foo();
echo $foo->method("param");]
?>
#output:
Fatal error: Cannot redeclare Foo::method() in class_overload.php on line 6
why?
we can not create the same method name.