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
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
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
argsare all numeric, the keys are ignored and each element will be passed tocallbackas a positional argument, in order.If any keys of
argsare strings, those elements will be passed tocallbackas named arguments, with the name given by the key.It is a fatal error to have a numeric key in
argsappear after a string key, or to have a string key that does not match the name of any parameter ofcallback.
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
- call_user_func() - Call the callback given by the first parameter
- ReflectionFunction::invokeArgs() - Invokes function args
- ReflectionMethod::invokeArgs() - Invoke args
add a note
User Contributed Notes 4 notes
admin at torntech dot com ¶
9 years ago
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', $args);
?>
alangiderick at gmail dot com ¶
1 year ago
It's quite interesting reading the notes in this page especially the one that mentions the difference between argument unpacking being significantly faster than calling `call_user_func_array()` directly by admin at torntech dot com.
This is true for PHP 5 but as from PHP 7.0+, there is no significant difference in the run-time between these two mechanisms of operation. The time taken is almost, if not the same for both operations, so this is already something that tells me that the PHP run-time environment has changed quite a lot (for the PHP 7 rewrite).
I used the example from admin at torntech dot com to check this hypothesis.
james at gogo dot co dot nz ¶
19 years ago
Be aware the call_user_func_array always returns by value, as demonstrated here...
<?php
function &foo(&$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;
}
?>
