Les valeurs de retour
$ wget http://www.php.net/get/php_manual_en.tar.gz/from/a/mirror
$ grep -l "\$\.\.\." php-chunked-xhtml/function.*.html
List of functions that accept variable arguments.
<?php
array_diff_assoc()
array_diff_key()
array_diff_uassoc()
array()
array_intersect_ukey()
array_map()
array_merge()
array_merge_recursive()
array_multisort()
array_push()
array_replace()
array_replace_recursive()
array_unshift()
call_user_func()
call_user_method()
compact()
dba_open()
dba_popen()
echo()
forward_static_call()
fprintf()
fscanf()
httprequestpool_construct()
ibase_execute()
ibase_set_event_handler()
ibase_wait_event()
isset()
list()
maxdb_stmt_bind_param()
maxdb_stmt_bind_result()
mb_convert_variables()
newt_checkbox_tree_add_item()
newt_grid_h_close_stacked()
newt_grid_h_stacked()
newt_grid_v_close_stacked()
newt_grid_v_stacked()
newt_win_choice()
newt_win_entries()
newt_win_menu()
newt_win_message()
newt_win_ternary()
pack()
printf()
register_shutdown_function()
register_tick_function()
session_register()
setlocale()
sprintf()
sscanf()
unset()
var_dump()
w32api_deftype()
w32api_init_dtype()
w32api_invoke_function()
wddx_add_vars()
wddx_serialize_vars()
?>
Fonctions variables
PHP supporte le concept de fonctions variables. Cela signifie que si le nom d'une variable est suivi de parenthèses, PHP recherchera une fonction de même nom, et essaiera de l'exécuter. Cela peut servir, entre autres, pour faire des fonctions de rappel, des tables de fonctions...
Les fonctions variables ne peuvent pas fonctionner avec les éléments de langage comme les echo(), print(), unset(), isset(), empty(), include(), require() etc. Vous devez utiliser votre propre gestion de fonctions pour utiliser un de ces éléments de langages comme fonctions variables.
Exemple #1 Exemple de fonction variable
<?php
function foo() {
echo "dans foo()<br />\n";
}
function bar($arg = '')
{
echo "Dans bar(); l'argument était '$arg'.<br />\n";
}
// Ceci est une fonction détournée de echo
function echoit($string)
{
echo $string;
}
$func = 'foo';
$func(); // Appel foo()
$func = 'bar';
$func('test'); // Appel bar()
$func = 'echoit';
$func('test'); // Appel echoit()
?>
Vous pouvez aussi appeler une méthode d'un objet en utilisant le système des fonctions variables.
Exemple #2 Exemple de méthode variable
<?php
class Foo
{
function Variable()
{
$name = 'Bar';
$this->$name(); // Appelle la méthode Bar()
}
function Bar()
{
echo "C'est Bar";
}
}
$foo = new Foo();
$funcname = "Variable";
$foo->$funcname(); // Appelle $foo->Variable()
?>
Lors de l'appel à des méthodes statiques, l'appel fonction est meilleur que l'opérateur de propriété statique :
Exemple #3 Exemple de méthode variable avec des propriétés statiques
<?php
class Foo
{
static $variable = 'static property';
static function Variable()
{
echo 'Method Variable called';
}
}
echo Foo::$variable; // Ceci affiche 'static property'. Il est nécessaire d'avoir une $variable dans le contexte.
$variable = "Variable";
Foo::$variable(); // Ceci appelle $foo->Variable(), lisant ainsi la $variable depuis le contexte.
?>
Voir aussi call_user_func(), les variables variables et function_exists().
add a note
User Contributed Notes
Fonctions variables
Anonymous
27-Jun-2011 11:20
imurnane at internode on net
02-May-2011 03:05
Create and call a dynamically named function
<?php
$tmp = "foo";
$$tmp = function() {
global $tmp;
echo $tmp;
};
$$tmp();
?>
Outputs "foo"
michalmojz at gmail dot com
29-Jan-2011 01:51
You can make dynamic functions as well.
For example
<?php
$myFunction = function() {
echo 1;
};
if(is_callable($myFunction)) {
$myFunction();
}
?>
AnonymousPoster at disposeamail dot com
03-May-2010 02:20
Variable functions allows higher-order programming.
Here is the classical map example.
<?php
/*
* Map function. At each $element of the $list, calls $fun([$arg1,[$arg2,[...,]],$element,$accumulator),
* stores the return value into $accumulator for the next loop. Returns the last return value of the function,
*
* Notes : uses call_user_func_array() so passing parameters doesn't depend on $fun signature
* It also returns FALSE upon error.
* Please check the php documentation for more information
*/
function map($fun, $list,$params=array()){
$acc=NULL;
$last=array_push($params, NULL,$acc)-1; // alloc $element and $acc at the end
foreach($list as $params[$last-1]){
$params[$last]=call_user_func_array($fun , $params );
}
$acc=array_pop($params);
return $acc;
}
function add($element,$acc){ // maybe only with multi-length function
if ($acc == NULL);
return $acc=$element+$acc;
}
$result=0;
$result=addTo($result,1);
$result=addTo($result,2);
$result=addTo($result,3);
echo "result = $result\n";
$result=0;
$result=map('addTo',array(1,2,3));
echo "result= $result\n";
?>
boards at gmail dot com
22-Jan-2006 10:07
If you want to call a static function (PHP5) in a variable method:
Make an array of two entries where the 0th entry is the name of the class to be invoked ('self' and 'parent' work as well) and the 1st entry is the name of the function. Basically, a 'callback' variable is either a string (the name of the function) or an array (0 => 'className', 1 => 'functionName').
Then, to call that function, you can use either call_user_func() or call_user_func_array(). Examples:
<?php
class A {
protected $a;
protected $c;
function __construct() {
$this->a = array('self', 'a');
$this->c = array('self', 'c');
}
static function a($name, &$value) {
echo $name,' => ',$value++,"\n";
}
function b($name, &$value) {
call_user_func_array($this->a, array($name, &$value));
}
static function c($str) {
echo $str,"\n";
}
function d() {
call_user_func_array($this->c, func_get_args());
}
function e() {
call_user_func($this->c, func_get_arg(0));
}
}
class B extends A {
function __construct() {
$this->a = array('parent', 'a');
$this->c = array('self', 'c');
}
static function c() {
print_r(func_get_args());
}
function d() {
call_user_func_array($this->c, func_get_args());
}
function e() {
call_user_func($this->c, func_get_args());
}
}
$a =& new A;
$b =& new B;
$i = 0;
A::a('index', $i);
$a->b('index', $i);
$a->c('string');
$a->d('string');
$a->e('string');
# etc.
?>
Storm
03-May-2005 08:34
This can quite useful for a dynamic database class:
(Note: This just a simplified section)
<?php
class db {
private $host = 'localhost';
private $user = 'username';
private $pass = 'password';
private $type = 'mysqli';
public $lid = 0;
// Connection function
function connect() {
$connect = $this->type.'_connect';
if (!$this->lid = $connect($this->host, $this->user, $this->pass)) {
die('Unable to connect.');
}
}
}
$db = new db;
$db->connect();
?>
Much easier than having multiple database classes or even extending a base class.
ian at NO_SPAM dot verteron dot net
20-Dec-2002 07:33
A good method to pass around variables containing function names within some class is to use the same method as the developers use in preg_replace_callback - with arrays containing an instance of the class and the function name itself.
function call_within_an_object($fun)
{
if(is_array($fun))
{
/* call a function within an object */
$fun[0]->{$fun[1]}();
}
else
{
/* call some other function */
$fun();
}
}
function some_other_fun()
{
/* code */
}
class x
{
function fun($value)
{
/* some code */
}
}
$x = new x();
/* the following line calls $x->fun() */
call_within_an_object(Array($x, 'fun'));
/* the following line calls some_other_fun() */
call_within_an_object('some_other_fun');
madeinlisboa at yahoo dot com
05-Sep-2002 05:14
Finally, a very easy way to call a variable method in a class:
Example of a class:
class Print() {
var $mPrintFunction;
function Print($where_to) {
$this->mPrintFunction = "PrintTo$where_to";
}
function PrintToScreen($content) {
echo $content;
}
function PrintToFile($content) {
fputs ($file, $contents);
}
.. .. ..
// first, function name is parsed, then function is called
$this->{$this->mPrintFunction}("something to print");
}
msmith at pmcc dot com
02-May-2002 04:49
Try the call_user_func() function. I find it's a bit simpler to implement, and at very least makes your code a bit more readable... much more readable and simpler to research for someone who isn't familiar with this construct.
anpatel at NOSPAM_cbu dot edu
17-Mar-2002 09:11
Yes interpolation can be very tricky. I suggest that you always use parenthesis, or curly brackets(whichever applies) to make your expression clear.
Dont ever depend on a language's expression parse preference order.
retro at enx dot org
13-Jan-2002 07:18
Another way to have php parse a variable within an object as a function is to simply set a temporary variable to its value. For example:
$obj->myfunction = "foo";
$x = $obj->myfunction;
$x(); // calls the function named "foo"