Llamadas de retorno
Note that (e.g.) usort calls on static methods of classes in a namespace need to be laid out as follows:
usort($arr, array('\Namespace\ClassName', 'functionName'));
Pseudo tipos y variables usadas en esta documentación
mixed
mixed indica que un parámetro puede aceptar múltiples tipos (pero no necesariamente todos).
gettype(), por ejemplo, puede aceptar todos los tipos PHP, mientras que str_replace() sólo acepta strings y arrays.
Llamada de retorno
Los pseudo-tipos callback fueron usados en está documentación antes de que la sugerencia de tipo callable fuera introducida en PHP 5.4. Significan exactamente lo mismo.
void
void como un tipo de variable de retorno significa que el valor de retorno no es útil. void en una lista de parámetros significa que la función no acepta ningún parámetro.
...
$... en el prototipo de funciones significa
and so on. Este nombre de variable se usa cuando una función
puede tomar un número infinito de argumentos.
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User Contributed Notes
Pseudo tipos y variables usadas en esta documentación
liam at helios-sites dot com
06-Dec-2010 04:44
michael dot martinek at gmail dot com
29-Aug-2009 09:20
The documentation is a little confusing, and with the recent OO changes it adds a little more to the confusion.
I was curious whether you could pass an object through the user func, modify it in that callback and have the actual object updated or whether some cloning was going on behind the scenes.
<?php
class Test
{
var $sValue = 'abc';
function testing($objTest)
{
$objTest->sValue = '123';
}
}
$obj = new Test();
call_user_func(array($obj, 'testing'), $obj);
var_dump($obj);
?>
This works as expected: The object is not cloned, and $sValue is properly set to '123'. With the OO changes in PHP 5, you don't need to do "function testing(&$objTest)" as it is already passed by reference.
phpguy at lifetoward dot com
11-Jun-2009 05:44
I noticed two important thing about putting callbacks into an arg list when calling a function:
1. The function to which the callback refers must be defined earlier in the source stream. So for example:
function main() {...; usort($array, 'sortfunction'); ... }
function sortfunction($a, $b){ return 0; }
Will NOT work, but this will:
function sortfunction($a, $b){ return 0; }
function main() {...; usort($array, 'sortfunction'); ... }
2. It's not really just a string. For example, this doesn't work:
usort($array, ($reverse?'reversesorter':'forwardsorter'));
I found these two discoveries quite counterintuitive.
sahid dot ferdjaoui at gmail dot com
20-Apr-2009 03:19
An example with PHP 5.3 and lambda functions
<?php
array_map (function ($value) {
return new MyFormElement ($value);
}, $_POST);
?>
Hayley Watson
23-May-2007 10:44
The mixed pseudotype is explained as meaning "multiple but not necessarily all" types, and the example of str_replace(mixed, mixed, mixed) is given where "mixed" means "string or array".
Keep in mind that this refers to the types of the function's arguments _after_ any type juggling.
levi at alliancesoftware dot com dot au
08-Feb-2007 02:44
Parent methods for callbacks should be called 'parent::method', so if you wish to call a non-static parent method via a callback, you should use a callback of
<?
// always works
$callback = array($this, 'parent::method')
// works but gives an error in PHP5 with E_STRICT if the parent method is not static
$callback array('parent', 'method');
?>
Edward
01-Feb-2007 02:15
To recap mr dot lilov at gmail dot com's comment: If you want to pass a function as an argument to another function, for example "array_map", do this:
regular functions:
<?
array_map(intval, $array)
?>
static functions in a class:
<?
array_map(array('MyClass', 'MyFunction'), $array)
?>
functions from an object:
<?
array_map(array($this, 'MyFunction'), $array)
?>
I hope this clarifies things a little bit