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call_user_func_array
Call a callback with an array of parameters
Description
mixed call_user_func_array(callable $callback, array $args)
Parameters
-
callback
-
The callable to be called.
-
args
-
The parameters to be passed to the callback, as an array.
If the keys of args are all numeric,
the keys are ignored and each element will be passed to
callback as a positional argument, in
order.
If any keys of args are strings,
those elements will be passed to callback
as named arguments, with the name given by the key.
It is a fatal error to have a numeric key in args
appear after a string key, or to have a string key that does not
match the name of any parameter of callback.
Return Values
Returns the return value of the callback, or false on error.
Examples
Example #1 call_user_func_array example
<?php
function foobar($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:
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
- ReflectionFunction::invokeArgs
- ReflectionMethod::invokeArgs
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