PHP: usort with closure syntax "use()" [duplicate] - php

Question

This question already has answers here:
Possible to pass a closure to usort in PHP?
(2 answers)
How can I sort arrays and data in PHP?
(14 answers)
Closed 2 years ago.
EDIT: I rewrote my post in order to be clearer and provide a standalone case with real values (no Ajax anymore).
I have 2 arrays that are exactly identical except that one has the same values but cleaned (html, special chars, etc..).
I would like to evaluate the sorting against "arrayClean" but to sort "arrayOriginal" instead (not arrayClean) according to that evaluation.
So, this is what I have:
<?php
$arrayOriginal = array(
array('id' => '100','surface' => '<span>300</span>','whatever' => 'qSDqsd'),
array('id' => '5465','surface' => '100 ch','whatever' => 'ghjkghjk'),
array('id' => '40489','surface' => '<b>1000</b>','whatever' => 'fgsdfg')
);
$arrayClean = array(
array('id' => '100','surface' => '300','whatever' => 'qSDqsd'),
array('id' => '5465','surface' => '100','whatever' => 'ghjkghjk'),
array('id' => '40489','surface' => '1000','whatever' => 'fgsdfg')
);
usort($arrayOriginal, function($a, $b) use (&$arrayClean) {
return $a['surface'] < $b['surface'];
});
echo '<pre>'; print_r($arrayOriginal); echo '</pre>';
?>
here is what I get (which is wrong as the arrayClean doesn't seem to be taken into account for the sorting) :
Array
(
[0] => Array
(
[id] => 100
[surface] => <span>300</span>
[whatever] => qSDqsd
)
[1] => Array
(
[id] => 40489
[surface] => <b>1000</b>
[pwhatever] => fgsdfg
)
[2] => Array
(
[id] => 5465
[surface] => 100 ch
[whatever] => ghjkghjk
)
)
But if I use arrayClean alone, just to check if the sorting script is right:
usort($arrayClean, function($a, $b) {
return $a['surface'] < $b['surface'];
});
echo '<pre>'; print_r($arrayClean); echo '</pre>';
Then the result is what I expect it to be:
Array
(
[0] => Array
(
[id] => 40489
[surface] => 1000
[whatever] => fgsdfg
)
[1] => Array
(
[id] => 100
[surface] => 300
[whatever] => qSDqsd
)
[2] => Array
(
[id] => 5465
[surface] => 100
[whatever] => ghjkghjk
)
)
So it seems that evaluating arrayClean but sorting arrayOriginal accordingly doesn't work. It only evaluates AND sort arrayOriginal.
Do I use "use()" wrong ? Should I use something else ?
Thank you.

Answer 1

Assuming both arrays are sorted by a common factor (i.e. id).
uksort($arrayOriginal, function($a, $b) use ($arrayClean) {
return $arrayClean[$a]['surface'] < $arrayClean[$b]['surface'];
});
Emphasising once more, to make it work, both arrays MUST contain elements in the same order. In your case elements of both arrays MUST come in the following order (by id): 100, 5465, 40489
BUT I'd rather do something like:
usort($arrayOriginal, function($a, $b) {
return yourSurfaceCleanMethod($arrayOriginal['surface']) < yourSurfaceCleanMethod($arrayOriginal['surface']);
});
All depends on your needs, of course, but if you are using $arrayClean only as a reference for sorting original array and you have that yourSurfaceCleanMethod handy, I'd definitely do the above.

Answer 2

I think the arrayClean is not needed if your arrayOriginal should be sorted according to the content of the HTML tags.
strip_tags() can be used for this in your sort function.
usort($arrayOriginal, function($a, $b) {
return strip_tags($b['surface']) <=> strip_tags($a['surface']);
});
Note: Use the spaceship operator <=> to get correct comparison results 1, 0 and -1.

Answer 3

I accepted Nemoden's answer as a courtesy because technically it answered the question according to its scope (the test case as presented). But here is the solution I found that works best for me :
$arrayOriginal = array(
array('id' => '100','surface' => '<span>300</span>','whatever' => 'qSDqsd'),
array('id' => '5465','surface' => '100 ch','whatever' => 'ghjkghjk'),
array('id' => '40489','surface' => '<b>1000</b>','whatever' => 'fgsdfg')
);
$arrayClean = array(
array('id' => '100','surface' => '300','whatever' => 'qSDqsd'),
array('id' => '5465','surface' => '100','whatever' => 'ghjkghjk'),
array('id' => '40489','surface' => '1000','whatever' => 'fgsdfg')
);
$surface = array_column($arrayClean, 'Surface');
array_multisort($surface, SORT_DESC, SORT_REGULAR, $arrayOriginal);
And then I get this output, which is EXACTLY what I want:
Array
(
[0] => Array
(
[id] => 40489
[surface] => <b>1000</b>
[whatever] => fgsdfg
)
[1] => Array
(
[id] => 100
[surface] => <span>300</span>
[whatever] => qSDqsd
)
[2] => Array
(
[id] => 5465
[surface] => 100 ch
[whatever] => ghjkghjk
)
)
The answer of Nemoden was very helpful BUT it gave me this, for whatever reason:
Array
(
[1] => Array
(
[id] => 40489
[surface] => <b>1000</b>
[whatever] => fgsdfg
)
[0] => Array
(
[id] => 100
[surface] => <span>300</span>
[whatever] => qSDqsd
)
[2] => Array
(
[id] => 5465
[surface] => 100 ch
[whatever] => ghjkghjk
)
)
The sub arrays are PRINTED in the right order but the sub arrays indexes weren't changed. So when exporting to javascript "arrayOriginal", it would come back to its initial sorting because the sub arrays would be re-ordered according to their indexes again. At least, that's what I experienced.
Anyway, now the problem is solved and the answers I got here were very helpful.
Thank you.