Programming Forums > Web Development and Design > PHP

woozy · Mar 14th, 2007, 5:45 PM

Okay, I want to write some in which I have an a bunch of values (let's say in an array called $params) and I want to call a function with those as parameters.

That is I want a line of code like:

do_it($param[0], $param[1], .... ,$param[n]);

How do I do that.

(And no, I do not want to have to rewrite the function do_it() so that it takes a single array argument.)

Thanks,
woozy

DaWei · Mar 14th, 2007, 6:39 PM

Then you'll have to pass them individually, which is dumb. Pass the array. What you want to do, and what you'll ultimately be paid to do (if you're serious) are two different things.

Arevos · Mar 14th, 2007, 7:10 PM

call_user_func_array is one option, but as has been mentioned, why don't you just rewrite the function? It's not like it would take a minute to do so.

woozy · Mar 14th, 2007, 7:23 PM

Well the problem is that function that is called is variable and I don't want to have to rewrite all the possible functions it code be to a standard I find stupid.

The call_user_func_array() *almost does what I want.

That is:

(Toggle Plain Text)

call_user_func_array("do_it", $params);

is the same thing as

(Toggle Plain Text)

doit($params[0],....,$params[n]);

That would be TERRIFIC, except the called functions must have a string function name. The functions I'm concered with are class methods. How do you refer to *those* by string?

My code is really something like this:

(Toggle Plain Text)

class FOO{
  function showObject($object [, param1, param2, .... ]){
    $object->show(param1, param2, ....);
  }
}

where the "show" function can vary as can it's parameters depending on what class of object $object is.

I can do this with

(Toggle Plain Text)

function($object){
 $params = array_slice(func_get_args(), 1);
 call_user_func_array(string that is $object->show, $params);
}

*except* I don't know how to figure string that is $object->show.

Arggh.

woozy · Mar 14th, 2007, 8:21 PM

Ah!

call_user_method_array()...

(Toggle Plain Text)

call_user_method_array("do_it", $object, $params);

does the same as

(Toggle Plain Text)

$object->do_it($params[0],...$params[n]);

A bit kludgy and contrived looking (I kind of thought there might be some function like "to_list($params)" to convert an array into a flow of values) but it does exactly what I wanted. Well, for now...

woozy · Mar 14th, 2007, 8:53 PM

...or I could use

call_user_func_array(array(&$object, "do_it"), $params);

as call_user_method is deprecated...

Styx · Mar 14th, 2007, 11:56 PM

For this purpose, you could also use:

(Toggle Plain Text)

function showObject($object, $params)
{
  $string = '';
  for ($i = 0; $i < count($params); $i++)
    $string .= (($i > 0) ? ', ' : '') . "\$params[$i]";

  eval("$object::show($string);");
}

but call_user_func_array is shorter

woozy · Mar 15th, 2007, 2:34 AM

Quote:

Originally Posted by Styx

For this purpose, you could also use:

(Toggle Plain Text)

 
...
 eval("$object::show($string);");
...

That's good to know. Thanks. The above seems kind of kludgy but it's good to have a few strategems when you get stuck.

I'd like something that feels more ... "holistic"... than refering to functions obliquely by quoted strings but one can't have everything.

You can convert a series of values into an array, so it seems like it'd be nice to be able to convert an array into a series of values. But so far as I can tell PHP simply doesn't have a way of doing this.

I guess call_user_func_array is PHP's solution but it seems so... indirect.

Oh well. At least it works.

Mar 14th, 2007, 5:45 PM	#1
woozy Newbie Join Date: Mar 2007 Posts: 15 Rep Power: 0	Calling a function with an indeterminate number of arguments Okay, I want to write some in which I have an a bunch of values (let's say in an array called $params) and I want to call a function with those as parameters. That is I want a line of code like: do_it($param[0], $param[1], .... ,$param[n]); How do I do that. (And no, I do not want to have to rewrite the function do_it() so that it takes a single array argument.) Thanks, woozy

Mar 14th, 2007, 6:39 PM	#2
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Then you'll have to pass them individually, which is dumb. Pass the array. What you want to do, and what you'll ultimately be paid to do (if you're serious) are two different things. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Mar 14th, 2007, 7:23 PM	#4
woozy Newbie Join Date: Mar 2007 Posts: 15 Rep Power: 0	Well the problem is that function that is called is variable and I don't want to have to rewrite all the possible functions it code be to a standard I find stupid. The call_user_func_array() almost does what I want. That is: (Toggle Plain Text) call_user_func_array("do_it", $params); call_user_func_array("do_it", $params); is the same thing as (Toggle Plain Text) doit($params[0],....,$params[n]); doit($params[0],....,$params[n]); That would be TERRIFIC, except the called functions must have a string function name. The functions I'm concered with are class methods. How do you refer to those* by string? My code is really something like this: (Toggle Plain Text) class FOO{ function showObject($object [, param1, param2, .... ]){ $object->show(param1, param2, ....); } } class FOO{ function showObject($object [, param1, param2, .... ]){ $object->show(param1, param2, ....); } } where the "show" function can vary as can it's parameters depending on what class of object $object is. I can do this with (Toggle Plain Text) function($object){ $params = array_slice(func_get_args(), 1); call_user_func_array(string that is $object->show, $params); } function($object){ $params = array_slice(func_get_args(), 1); call_user_func_array(string that is $object->show, $params); } except I don't know how to figure string that is $object->show. Arggh.

Mar 14th, 2007, 8:21 PM	#5
woozy Newbie Join Date: Mar 2007 Posts: 15 Rep Power: 0	Ah! call_user_method_array()... (Toggle Plain Text) call_user_method_array("do_it", $object, $params); call_user_method_array("do_it", $object, $params); does the same as (Toggle Plain Text) $object->do_it($params[0],...$params[n]); $object->do_it($params[0],...$params[n]); A bit kludgy and contrived looking (I kind of thought there might be some function like "to_list($params)" to convert an array into a flow of values) but it does exactly what I wanted. Well, for now...

Mar 14th, 2007, 8:53 PM	#6
woozy Newbie Join Date: Mar 2007 Posts: 15 Rep Power: 0	..or I could ...or I could use call_user_func_array(array(&$object, "do_it"), $params); as call_user_method is deprecated...

Mar 14th, 2007, 7:10 PM	#3
Arevos Programming Guru Join Date: Aug 2005 Location: England Posts: 1,499 Rep Power: 5	call_user_func_array is one option, but as has been mentioned, why don't you just rewrite the function? It's not like it would take a minute to do so.

Mar 14th, 2007, 11:56 PM	#7
Styx Programmer Join Date: Mar 2007 Posts: 39 Rep Power: 0	For this purpose, you could also use: (Toggle Plain Text) function showObject($object, $params) { $string = ''; for ($i = 0; $i < count($params); $i++) $string .= (($i > 0) ? ', ' : '') . "\$params[$i]"; eval("$object::show($string);"); } function showObject($object, $params) { $string = ''; for ($i = 0; $i < count($params); $i++) $string .= (($i > 0) ? ', ' : '') . "\$params[$i]"; eval("$object::show($string);"); } but call_user_func_array is shorter

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Programming Forums > Web Development and Design > PHP

Calling a function with an indeterminate number of arguments