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call_user_func_array

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

call_user_func_array — Call a callback with an array of parameters

Description

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

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

Parameters

callback

The callable to be called.

args

The parameters to be passed to the callback, as an array.

If the keys of args are all numeric, the keys are ignored and each element will be passed to callback as a positional argument, in order.

If any keys of args are strings, those elements will be passed to callback as named arguments, with the name given by the key.

It is a fatal error to have a numeric key in args appear after a string key, or to have a string key that does not match the name of any parameter of callback.

Return Values

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

Changelog

Version Description
8.0.0 args keys will now be interpreted as parameter names, instead of being silently ignored.

Examples

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"));
?>

The above example will output something similar to:

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";
    }
}

call_user_func_array(__NAMESPACE__ .'\Foo::test', array('Hannes'));

call_user_func_array(array(__NAMESPACE__ .'\Foo', 'test'), array('Philip'));

?>

The above example will output something similar to:

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)));

?>

The above example will output:

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";

?>

The above example will output:

function mega $a=55
global $bar=55

Example #5 call_user_func_array() using named arguments

<?php
function foobar($first, $second) {
    echo __FUNCTION__, " got $first and $second\n";
}

// Call the foobar() function with named arguments in non-positional order
call_user_func_array("foobar", array("second" => "two", "first" => "one"));

// Call the foobar() function with one named argument
call_user_func_array("foobar", array("foo", "second" => "bar"));

// Fatal error: Cannot use positional argument after named argument
call_user_func_array("foobar", array("first" => "one", "bar"));

?>

The above example will output something similar to:

foobar got one and two
foobar got foo and bar

Fatal error: Uncaught Error: Cannot use positional argument after named argument

Notes

Note:

Callbacks registered with functions such as call_user_func() and call_user_func_array() will not be called if there is an uncaught exception thrown in a previous callback.

See Also

© 1997–2023 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.call-user-func-array.php