call_user_func
PHP 4, PHP 5, PHP 7, PHP 8
call_user_func - Call the callback given by the first parameter
Manual
call_user_func(
callable$callback,
... mixed$args ): mixed
Calls the callback given by the first parameter and passes the remaining parameters as arguments.
Parameters
- callback
-
The callable to be called.
- args
-
Zero or more parameters to be passed to the callback.
Note:
Note that the parameters for call_user_func are not passed by reference.
call_user_func example and references<?php
error_reporting(E_ALL);
function increment(&$var)
{
$var++;
}
$a = 0;
call_user_func('increment', $a);
echo $a."\n";
// it is possible to use this instead
call_user_func_array('increment', array(&$a));
echo $a."\n";
// it is also possible to use a variable function
$increment = 'increment';
$increment($a);
echo $a."\n";
?>The above example will output:
Warning: Parameter 1 to increment() expected to be a reference, value given in …
0
1
2
Return Values
Returns the return value of the callback.
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.