(PHP 4, PHP 5)
call_user_func — Call the callback given by the first parameter
Calls the callback given by the first parameter and passes
the remaining parameters as arguments.
callback
The callable to be called.
parameter
Zero or more parameters to be passed to the callback.
Note:
Note that the parameters for call_user_func() are not passed by reference.
Example #1 call_user_func() example and references
<?php
error_reporting(E_ALL);
function increment(&$var)
{
$var++;
}
$a = 0;
call_user_func('increment', $a);
echo $a."\n";
call_user_func_array('increment', array(&$a)); // You can use this instead before PHP 5.3
echo $a."\n";
?>以上例程会输出：
0 1
Returns the return value of the callback, or FALSE on error.
| 版本 | 说明 |
|---|---|
| 5.3.0 |
The interpretation of object oriented keywords like parent
and self has changed. Previously, calling them using the
double colon syntax would emit an E_STRICT warning because
they were interpreted as static.
|
Example #2 call_user_func() example
<?php
function barber($type)
{
echo "You wanted a $type haircut, no problem\n";
}
call_user_func('barber', "mushroom");
call_user_func('barber', "shave");
?>
以上例程会输出：
You wanted a mushroom haircut, no problem You wanted a shave haircut, no problem
Example #3 call_user_func() using namespace name
<?php
namespace Foobar;
class Foo {
static public function test() {
print "Hello world!\n";
}
}
call_user_func(__NAMESPACE__ .'\Foo::test'); // As of PHP 5.3.0
call_user_func(array(__NAMESPACE__ .'\Foo', 'test')); // As of PHP 5.3.0
?>
以上例程会输出：
Hello world! Hello world!
Example #4 Using a class method with call_user_func()
<?php
class myclass {
static function say_hello()
{
echo "Hello!\n";
}
}
$classname = "myclass";
call_user_func(array($classname, 'say_hello'));
call_user_func($classname .'::say_hello'); // As of 5.2.3
$myobject = new myclass();
call_user_func(array($myobject, 'say_hello'));
?>
以上例程会输出：
Hello! Hello! Hello!
Example #5 Using lambda function with call_user_func()
<?php
call_user_func(function($arg) { print "[$arg]\n"; }, 'test'); /* As of PHP 5.3.0 */
?>
以上例程会输出：
[test]
Note:
在函数中注册有多个回调内容时(如使用 call_user_func() 与 call_user_func_array())，如在前一个回调中有未捕获的异常，其后的将不再被调用。