5.3.8, Why is func_num_args() not working on a Clusure?

13 years ago by Mark — view source — reply

unread

Hi,

Why is func_num_args not working on closures?
Example code (tested on PHP 5.3.8):

<?php

class Test
{
public function testClosure($oClosure)
{
echo '<pre>';
print_r(func_num_args($oClosure));
echo '<pre>';
}
}

$c = new Test();
$c->testClosure(function($arg1, $arg2){
});

That returns 1 (the num of args in which function the closure is
(testClosure), but not the number of args from the closure itself.
Now Reflection can be used to get the number of args but that is overkill!
Also when you would do print_r(func_get_args($oClosure)); you do get
"something" back including the arguments but no way (that i know) to use
them!

Just something that i wonder...
I would have expected num args to return the args of the function you
provide it..

Kind regards,
Mark

13 years ago by Rafael Kassner — view source — reply

unread

func_num_args() must be called inside the Closure to know the number
of arguments that it received. If you are calling outside, it returns
the number of arguments of your testClosure function. There is no
other way than Reflection to do this.

And, I think func_num_args() does not receive any parameter.

Hi,

Why is func_num_args not working on closures?
Example code (tested on PHP 5.3.8):

<?php

class Test
{
public function testClosure($oClosure)
{
echo '<pre>';
print_r(func_num_args($oClosure));
echo '<pre>';
}
}

$c = new Test();
$c->testClosure(function($arg1, $arg2){
});

That returns 1 (the num of args in which function the closure is
(testClosure), but not the number of args from the closure itself.
Now Reflection can be used to get the number of args but that is overkill!
Also when you would do print_r(func_get_args($oClosure)); you do get
"something" back including the arguments but no way (that i know) to use
them!

Just something that i wonder...
I would have expected num args to return the args of the function you
provide it..

Kind regards,
Mark

--
Atenciosamente,
Rafael Kassner

13 years ago by Gergo Erdosi — view source — reply

unread

Hi,

The function func_num_args() doesn't accept any parameters, so calling func_num_args($oClosure) is the same as calling simple func_num_args(). That's why it returns 1 instead of 2, which is I think the expected and correct behavior.

Gergo Erdosi

Hi,

Why is func_num_args not working on closures?
Example code (tested on PHP 5.3.8):

<?php

class Test
{
public function testClosure($oClosure)
{
echo '<pre>';
print_r(func_num_args($oClosure));
echo '<pre>';
}
}

$c = new Test();
$c->testClosure(function($arg1, $arg2){
});

That returns 1 (the num of args in which function the closure is
(testClosure), but not the number of args from the closure itself.
Now Reflection can be used to get the number of args but that is overkill!
Also when you would do print_r(func_get_args($oClosure)); you do get
"something" back including the arguments but no way (that i know) to use
them!

Just something that i wonder...
I would have expected num args to return the args of the function you
provide it..

Kind regards,
Mark

13 years ago by Rafael Kassner — view source — reply

unread

My bad, replied only to sender. Fixing it now.

Well, any time you need to know signature or another information about
a function or class method, you should use Reflection. func_num_args()
is useful for when you need a dynamic function, like this (an
hypothetic example using func_get_args(), but you can get the point).

function delete ()
{
$ids = func_get_args();
// implementation
}

$success = delete(1, 2, 7);

Then there is no point for the func_num_args() function to accept a
parameter at all if it takes the current function anyway.
I don't see this as a feature, more like a bug!

func_num_args() must be called inside the Closure to know the number of
arguments that it received. If you are calling outside, it returns the
number of arguments of your testClosude function. There is no other way than
Reflection to do this.

And, I thunk func_num_args() does not receive any parameter.

Hi,

Why is func_num_args not working on closures?
Example code (tested on PHP 5.3.8):

<?php

class Test
{
public function testClosure($oClosure)
{
echo '<pre>';
print_r(func_num_args($oClosure));
echo '<pre>';
}
}

$c = new Test();
$c->testClosure(function($arg1, $arg2){
});

That returns 1 (the num of args in which function the closure is
(testClosure), but not the number of args from the closure itself.
Now Reflection can be used to get the number of args but that is
overkill!
Also when you would do print_r(func_get_args($oClosure)); you do get
"something" back including the arguments but no way (that i know) to use
them!

Just something that i wonder...
I would have expected num args to return the args of the function you
provide it..

Kind regards,
Mark

--
Atenciosamente,
Rafael Kassner