PHP efficiency and multidimension array count

[dagnasty]

I have 3 questions that I've been unable to find understandable google results for.

1. I have a variable that contains the HTML of a page and was wondering if it'd be better to unset() it after I'm done with it, or leave it as is. Will the time spent doing the unset() not be worthwhile beceause of the time it takes the execute the function on a variable the string size of an HTML page?

2. I have a multidimensional array and want to count the (not sure with terminology, so I'll use and X) X part of this array, how would I go about it?
ex: $array[0][X];

3. This question has something to do with regexp but I don't feel it's worth posting a query in the regexp section.
When doing a preg_match is there a way to only get the information between a pattern instead of returning the pattern and the stuff between it.

ex:
[code]
$lookhere = "stuff here <tag>the good stuff</tag> stuff there";


preg_match("/<tag>([^`]*?)<\/tag>/", $lookhere, $output);[/code]

this would turn out "<tag>the good stuff</tag>" but what I want is just "the good stuff"

Thanks.

[scliburn]

$output['0'] = "<tag>the good stuff</tag>"
but
$output['1'] = "the good stuff"

output is now an array.

[Barand]

Ans 2)

[code]
<?php
$a = array (
    array (1,2,3,4,5),
    array (6,7,8),
    array (9,0)
);

$counts = array();
foreach ($a as $k => $v) {
    $counts[$k] = count($v);
    $total += $counts[$k];
}
echo '<pre>', print_r($counts, true), $total, '</pre>';
?>
[/code]

[Caesar]

[quote author=scliburn link=topic=113388.msg460715#msg460715 date=1162322012]
$output['0'] = "<tag>the good stuff</tag>"
but
$output['1'] = "the good stuff"

output is now an array.
[/quote]

Or:

[quote]3. This question has something to do with regexp but I don't feel it's worth posting a query in the regexp section.
When doing a preg_match is there a way to only get the information between a pattern instead of returning the pattern and the stuff between it.[/quote]

[code]<?php

$lookhere = "stuff here <tag>the good stuff</tag> stuff there";
preg_match('/<tag>(.*)</tag>/',$lookhere,$output);

// $output will equal: Array ( [0] => the good stuff  [1] => the good stuff )

echo"$output[0]";

?>[/code]

[scliburn]

ans#1

actually opinion. Just unset it. It's sitting in memory otherwise. I aggregate data all day long, and resources are extremely valuable to me.

If it's not hurting anything leave alone. If you have resource intensive scripts, unset it. I didn't realize it took any real processing time to unset a scalar.

[sasa]

ans2[code]<?php
function MyCount($a) {
if (is_array($a)) {
$out = 0;
foreach ($a as $b) $out += MyCount($b);
return $out;
} else return 1;
}
$a = array (
    array (1,2,3,4,5,
    array(1,5,9)
    ),
    array (6,7,8),
    array (9,0)
);
echo MyCount($a);
?>[/code]

[mainewoods]

anser2
[code]<?php
    //get the number of elements in X in $array[0][X];
    $numelements = count($array[0]); //should do it
?>[/code]

[mainewoods]

answer1

it should auto unset itself after the php page finishes execution so you'll probably have no gain by unsetting it manually.

[dagnasty]

Thanks guys. Your information was very helpful.

The script is a VERY VERY VERY resource intensive one.

'nother quick question:

Does doing an unset on an array or a multidimensional array completely unset it?

[joshi_v]

It will depends on your code. see the examples.

[code]
<?php
// destroy a complete array.
unset ($foo);

// destroy a single element of an array
unset ($bar['quux']);

// destroy more than one variable
unset ($foo1, $foo2, $foo3);
?>

[/code]


Regards,

Joshi.