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call_user_func_array

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

call_user_func_array — Call a callback with an array of parameters

Descrierea

call_user_func_array ( callable $callback , array $args ) : mixed

Calls the callback given by the first parameter with the parameters in args.

Parametri

callback: The callable to be called.
args: The parameters to be passed to the callback, as an indexed array.

Valorile întoarse

Returns the return value of the callback, or false on error.

Exemple

Example #1 call_user_func_array() example


<?php
function foobar($arg, $arg2) {
    echo __FUNCTION__, " got $arg and $arg2\n";
}
class foo {
    function bar($arg, $arg2) {
        echo __METHOD__, " got $arg and $arg2\n";
    }
}


// Call the foobar() function with 2 arguments
call_user_func_array("foobar", array("one", "two"));

// Call the $foo->bar() method with 2 arguments
$foo = new foo;
call_user_func_array(array($foo, "bar"), array("three", "four"));
?>

Exemplul de mai sus va afișa ceva similar cu:

foobar got one and two
foo::bar got three and four

Example #2 call_user_func_array() using namespace name


<?php

namespace Foobar;

class Foo {
    static public function test($name) {
        print "Hello {$name}!\n";
    }
}

// As of PHP 5.3.0
call_user_func_array(__NAMESPACE__ .'\Foo::test', array('Hannes'));

// As of PHP 5.3.0
call_user_func_array(array(__NAMESPACE__ .'\Foo', 'test'), array('Philip'));

?>

Exemplul de mai sus va afișa ceva similar cu:

Hello Hannes!
Hello Philip!

Example #3 Using lambda function


<?php

$func = function($arg1, $arg2) {
    return $arg1 * $arg2;
};

var_dump(call_user_func_array($func, array(2, 4))); /* As of PHP 5.3.0 */

?>

Exemplul de mai sus va afișa:

int(8)

Example #4 Passing values by reference


<?php

function mega(&$a){
    $a = 55;
    echo "function mega \$a=$a\n";
}
$bar = 77;
call_user_func_array('mega',array(&$bar));
echo "global \$bar=$bar\n";

?>

Exemplul de mai sus va afișa:

function mega $a=55
global $bar=55

Note

Notă:
Before PHP 5.4, referenced variables in args are passed to the function by reference, regardless of whether the function expects the respective parameter to be passed by reference. This form of call-time pass by reference does not emit a deprecation notice, but it is nonetheless deprecated, and has been removed in PHP 5.4. Furthermore, this does not apply to internal functions, for which the function signature is honored. Passing by value when the function expects a parameter by reference results in a warning and having call_user_func() return false (there is, however, an exception for passed values with reference count = 1, such as in literals, as these can be turned into references without ill effects — but also without writes to that value having any effect —; do not rely in this behavior, though, as the reference count is an implementation detail and the soundness of this behavior is questionable).

Notă:
Funcțiile de apel invers înregistrate cu astfel de funcții ca call_user_func() și call_user_func_array() nu vor fi apelate dacă există o excepție neinterceptată emisă într-un apel precedent.

A se vedea și

call_user_func() - Call the callback given by the first parameter
ReflectionFunction::invokeArgs() - Invokes function args
ReflectionMethod::invokeArgs() - Invoke args

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User Contributed Notes 4 notes

down

admin at torntech dot com ¶

9 years ago


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

down

sebastian dot rapetti at tim dot it ¶

3 years ago


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);
?>

down

alangiderick at gmail dot com ¶

1 year ago


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.

down

-2

james at gogo dot co dot nz ¶

19 years ago


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;
    }
?>

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