PHP Manual: call_user

Description

mixed call_user_func ( callback function [, mixed parameter [, mixed ...]] )

Call a user defined function given by the function parameter. Take the following:

<?php
function barber($type) 
{
    echo "You wanted a $type haircut, no problem";
}
call_user_func('barber', "mushroom");
call_user_func('barber', "shave");
?>

Class methods may also be invoked statically using this function by passing array($classname, $methodname) to the function parameter.

<?php
class myclass {
    function say_hello() 
    {
        echo "Hello!\n";
    }
}

$classname = "myclass";

call_user_func(array($classname, 'say_hello'));
?>

Note: Note that the parameters for call_user_func() are not passed by reference.

<?php
function increment(&$var)
{
    $var++;
}

$a = 0;
call_user_func('increment', $a);
echo $a; // 0

call_user_func_array('increment', array(&$a)); // You can use this instead
echo $a; // 1
?>

See also: is_callable(), call_user_func_array(), and information about the callback type.