Re: [PHP] Nested functions
Thanks for the confirmations Torben.
Can one code user-defined functions nested within one another
Yes.
- and repeatedly execute them?
No. ;)
This is correct. As you know, the thing is that execution keeps running
into that function declaration every time the containing function is
run, tries to declare the function, and fails. Essentially: while you
*can* do nested functions in PHP, don't. :) There really isn't any good
reason to, anyway--except for (perhaps) a wee bit of namespace
clarification.
Namespace clarification is exactly what I had in mind - I am post-processing the n=0,
1, 1 results from a
preg_match_all() and figured that array_walk() would be faster than for{$i...} or
foreach(). However learning
that array_walk() demanded use of a function, that implied that my 'modular' function
would have to call a
(short) second to suit the command structure - thus the logic that nesting would 'keep
things together' in
reuse/restructure situations.
[As you will appreciate, the test bed code was almost directly out of the manual,
and was only being used so
that I could experiment/get my head around the command/and thereafter test the
efficiency criteria]
I thought I would ask, if only because other languages, even interpreted languages, do
cope with this
situation - but as you say, it is not a show-stopper
- a possible case for FUNCTION_once name() as per REQUIRE and INCLUDE?
Thanks again,
=dn
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[PHP] Nested functions
Hi,
Have been experimenting with the array_walk function and a little array debug print
facility, but ran into a
problem with nested functions. The code can be written with nested functions and
successfully executed once; but
when repeatedly executed an error appears.
Can one code user-defined functions nested within one another - and repeatedly execute
them?
The PHP Manual: Chapter 12. Functions, says:
A function may be defined using syntax such as the following:
...
Any valid PHP code may appear inside a function, even other
functions and class definitions.
Here is some test-bed code:
?php
Function ShowList( $title, $aList )
{
Function FnNested( $item, $key )
{
echo br$key= . $item . ~;
} //end of FnNested
echo brListing array=$title: n= . count( $aList );
array_walk( $aList, FnNested );
} //end of function ShowList
//mainline code
$aLocated = array( 'zero', 'one', 'two', 'three' );
ShowList( Located1, $aLocated );
ShowList( Located2, $aLocated );
?
Sample output:
FnShowList~
Listing array=Located1: n=4
0=zero~
1=one~
2=two~
3=three~
FnShowList~
Fatal error: Cannot redeclare fnnested() in c:\data\webs\webute_tst\l.php on line 6
Please advise,
=dn
WinNT 4.0 SP6a running PHP vn 4.0.6, Apache vn 1.3.20WinNT, MySQL vn 3.23.40-nt
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Re: [PHP] Nested functions
On Sat, 2002-02-09 at 15:40, DL Neil wrote:
Hi,
Have been experimenting with the array_walk function and a little array debug print
facility, but ran into a
problem with nested functions. The code can be written with nested functions and
successfully executed once; but
when repeatedly executed an error appears.
Can one code user-defined functions nested within one another
Yes.
- and repeatedly execute them?
No. ;)
The PHP Manual: Chapter 12. Functions, says:
A function may be defined using syntax such as the following:
...
Any valid PHP code may appear inside a function, even other
functions and class definitions.
This is correct. As you know, the thing is that execution keeps running
into that function declaration every time the containing function is
run, tries to declare the function, and fails. Essentially: while you
*can* do nested functions in PHP, don't. :) There really isn't any good
reason to, anyway--except for (perhaps) a wee bit of namespace
clarification.
Here is some test-bed code:
?php
Function ShowList( $title, $aList )
{
Function FnNested( $item, $key )
{
echo br$key= . $item . ~;
} //end of FnNested
echo brListing array=$title: n= . count( $aList );
array_walk( $aList, FnNested );
} //end of function ShowList
//mainline code
$aLocated = array( 'zero', 'one', 'two', 'three' );
ShowList( Located1, $aLocated );
ShowList( Located2, $aLocated );
?
There really isn't any reason to do this; you could achieve the same
thing like so:
?php
error_reporting(E_ALL);
function FnNested( $item, $key ) {
echo br$key= . $item . ~;
} //end of FnNested
function ShowList( $title, $aList ) {
echo brListing array=$title: n= . count( $aList );
array_walk( $aList, FnNested );
} //end of function ShowList
//mainline code
$aLocated = array( 'zero', 'one', 'two', 'three' );
ShowList( Located1, $aLocated );
ShowList( Located2, $aLocated );
?
Hope this helps,
Torben
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Re: [PHP] nested functions
elias wrote: good question...I might need an answer when you get one. Why? Ok, I have a perl-counter script which is included to shtml-pages with SSI. Now I want to add some PHP pages to my site. So I need a PHP-function that does the same as the perl-script does. In the script I have a lot of global variables and some auxiliary functions. In PHP these variables became local variables of the counter() function and the auxiliary functions became nested functions. The auxiliary nested functions have to have access to a lot of variables from the counter() function, and they even have to change them. I already added all the variables (some with call by reference) but I think it would have been easier if I had access the counter()-variables within the nested auxiliary functions direct. Hannes PS: I wonder why my original message does not appear in Outlook Express News-Folder... just the answers? -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
Re: [PHP] nested functions
On Wednesday 16 May 2001 12:12, Hannes Schmiderer wrote: elias wrote: good question...I might need an answer when you get one. Why? Ok, I have a perl-counter script which is included to shtml-pages with SSI. Now I want to add some PHP pages to my site. So I need a PHP-function that does the same as the perl-script does. In the script I have a lot of global variables and some auxiliary functions. In PHP these variables became local variables of the counter() function and the auxiliary functions became nested functions. The auxiliary nested functions have to have access to a lot of variables from the counter() function, and they even have to change them. I already added all the variables (some with call by reference) but I think it would have been easier if I had access the counter()-variables within the nested auxiliary functions direct. What about using classes instead of outer functions? Classes provide rather nice (nestable) scoping. -- Christian Reiniger LGDC Webmaster (http://sunsite.dk/lgdc/) Software is like sex: the best is for free -- Linus Torvalds -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
Re: [PHP] nested functions
What about using classes instead of outer functions? Classes provide rather nice (nestable) scoping. You're right! If I had written it from scratch classes would be the best way! Although, I'm a newbie and I haven't read the PHP object oriented capter yet ;-). Hannes -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
[PHP] nested functions
Is there no way to access the $x within the inner function:
function outer()
{
$x = 50;
function inner()
{
echo $x;
}
inner();
}
Global in the inner function does not work. I do not want to have $x global
for all.
Hannes Schmiderer
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Re: [PHP] nested functions
why don't you pass $x as an argument?
- Original Message -
From: Johannes Schmiderer [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: 2001. május 15. 23:41
Subject: [PHP] nested functions
Is there no way to access the $x within the inner function:
function outer()
{
$x = 50;
function inner()
{
echo $x;
}
inner();
}
Global in the inner function does not work. I do not want to have $x global
for all.
Hannes Schmiderer
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For additional commands, e-mail: [EMAIL PROTECTED]
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Re: [PHP] nested functions
good question...I might need an answer when you get one.
-elias
Johannes Schmiderer [EMAIL PROTECTED] wrote in message
9ds7le$caa$[EMAIL PROTECTED]">news:9ds7le$caa$[EMAIL PROTECTED]...
Is there no way to access the $x within the inner function:
function outer()
{
$x = 50;
function inner()
{
echo $x;
}
inner();
}
Global in the inner function does not work. I do not want to have $x
global
for all.
Hannes Schmiderer
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For additional commands, e-mail: [EMAIL PROTECTED]
To contact the list administrators, e-mail: [EMAIL PROTECTED]
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