call_user_func_array
(PHP 4 >= 4.0.4, PHP 5)
call_user_func_array — Вызывает пользовательскую функцию с массивом параметров
Описание
Вызывает пользовательскую функцию function , с параметрами из массива param_arr . Например:
Пример #1 Использование call_user_func_array()
<?php
function debug($var, $val)
{
echo "***DEBUGGING\nVARIABLE: $var\nVALUE:";
if (is_array($val) || is_object($val) || is_resource($val)) {
print_r($val);
} else {
echo "\n$val\n";
}
echo "***\n";
}
$c = mysql_connect();
$host = $_SERVER["SERVER_NAME"];
call_user_func_array('debug', array("host", $host));
call_user_func_array('debug', array("c", $c));
call_user_func_array('debug', array("_POST", $_POST));
?>
См. также call_user_func().
Коментарии
Be aware the call_user_func_array always returns by value, as demonstrated here...
<?php
function &foo(&$a)
{
return $a;
}
$b = 2;
$c =& call_user_func_array('foo', array(&$b));
$c++;
echo $b . ' ' . $c;
?>
outputs "2 3", rather than the expected "3 3".
Here is a function you can use in place of call_user_func_array which returns a reference to the result of the function call.
<?php
function &ref_call_user_func_array($callable, $args)
{
if(is_scalar($callable))
{
// $callable is the name of a function
$call = $callable;
}
else
{
if(is_object($callable[0]))
{
// $callable is an object and a method name
$call = "\$callable[0]->{$callable[1]}";
}
else
{
// $callable is a class name and a static method
$call = "{$callable[0]}::{$callable[1]}";
}
}
// Note because the keys in $args might be strings
// we do this in a slightly round about way.
$argumentString = array();
$argumentKeys = array_keys($args);
foreach($argumentKeys as $argK)
{
$argumentString[] = "\$args[$argumentKeys[$argK]]";
}
$argumentString = implode($argumentString, ', ');
// Note also that eval doesn't return references, so we
// work around it in this way...
eval("\$result =& {$call}({$argumentString});");
return $result;
}
?>
As of PHP 5.6 you can utilize argument unpacking as an alternative to call_user_func_array, and is often 3 to 4 times faster.
<?php
function foo ($a, $b) {
return $a + $b;
}
$func = 'foo';
$values = array(1, 2);
call_user_func_array($func, $values);
//returns 3
$func(...$values);
//returns 3
?>
Benchmarks from https://gist.github.com/nikic/6390366
cufa with 0 args took 0.43453288078308
switch with 0 args took 0.24134302139282
unpack with 0 args took 0.12418699264526
cufa with 5 args took 0.73408579826355
switch with 5 args took 0.49595499038696
unpack with 5 args took 0.18640494346619
cufa with 100 args took 5.0327250957489
switch with 100 args took 5.291127204895
unpack with 100 args took 1.2362589836121
Using PHP 8, call_user_func_array call callback function using named arguments if an array with keys is passed to $args parameter, if the array used has only values, arguments are passed positionally.
<?php
function test(string $param1, string $param2): void
{
echo $param1.' '.$param2;
}
$args = ['hello', 'world'];
//hello world
call_user_func_array('test', $args);
$args = ['param2' => 'world', 'param1' => 'hello'];
//hello world
call_user_func_array('test', $args);
$args = ['unknown_param' => 'hello', 'param2' => 'world'];
//Fatal error: Uncaught Error: Unknown named parameter $unknown_param
call_user_func_array('test', $args);
?>
It's quite interesting reading the notes in this page especially the one that mentions the difference between argument unpacking being significantly faster than calling `call_user_func_array()` directly by admin at torntech dot com.
This is true for PHP 5 but as from PHP 7.0+, there is no significant difference in the run-time between these two mechanisms of operation. The time taken is almost, if not the same for both operations, so this is already something that tells me that the PHP run-time environment has changed quite a lot (for the PHP 7 rewrite).
I used the example from admin at torntech dot com to check this hypothesis.