usort not working properly

[millercj]

I made a custom sort to reorder a multidimensional array of data pulled from a database. It seems to be sorting letters fine but doesn't work with numbers...which is what i need. If you can offer any suggestions they'd be appreciated.

 

	$sort_field = 5;
	function cmpi($a,$b) 
	{ 
		 global $sort_field; 
		 return strcmp($a[$sort_field], $b[$sort_field]); 
	} 
	usort($cartList, 'cmpi'); 

[sastro]

Can you post the result and what your expected result?

[millercj]

Sure,I'll make a chart like thing

 

 

Sort Order        $cartList

      1                    36

      3                    40

      4                    43

      5                    46

      6                    50

[bluejay002]

There are built in sorting functions for array in PHP.

 

If multidimensional array: array_multisort()

 

There are a lot of functions to check at:

 

sort(), arsort(), asort(), ksort(), krsort(), natsort(), natcasesort(), rsort(), usort(), array_multisort(), and uksort().

 

Does any of these work with what you need?

 

[millercj]

well...to be honest i'm not a sorting expert. I've only ever used a basic sort (because of lack of knowledge on the others) and that will always and only sort the first column [0] of the array. I need the 6th [5]

[bluejay002]

Try this if this works.

 

<?php
// $ar is a multidimensional array

array_multisort($ar[5], SORT_ASC, SORT_REGULAR);

// if string only, use SORT_STRING; or SORT_NUMERIC if numeric as it suggests.
?>

 

Jay

[millercj]

array_multisort($cartList[5], SORT_ASC, SORT_REGULAR);

 

Warning:  array_multisort(): Argument #1 is expected to be an array or a sort flag in /home/nutsab5/public_html/beta/phpscript/inlineCartView.php

 

[bluejay002]

oh my bad...

 

tr this instead, we will be dissecting it though:

 

<?php
// given they have something like this
$data = array();

$data[] = array('volume' => 67, 'edition' => 2);
$data[] = array('volume' => 86, 'edition' => 1);
$data[] = array('volume' => 85, 'edition' => 6);
$data[] = array('volume' => 98, 'edition' => 2);
$data[] = array('volume' => 86, 'edition' => 6);
$data[] = array('volume' => 67, 'edition' => 7);

// Obtain a list of columns
foreach ($data as $key => $row) {
    $volume[$key]  = $row['volume'];
    $edition[$key] = $row['edition'];
}

// Sort the data with volume descending, edition ascending
// Add $data as the last parameter, to sort by the common key
array_multisort($volume, SORT_DESC, $edition, SORT_ASC, $data);
?> 

 

can check this out? They should have common keys here... you can have an idea from here.

[millercj]

this is what I did...no errors but still not sorting it right though

 

foreach ($cartList as $key => $row) {
    $name[$key]  = $row[0];
    $price[$key] = $row[1];
    $qty[$key]  = $row[2];
    $sizedesc[$key] = $row[3];
    $image[$key]  = $row[4];
    $date[$key] = $row[5];
}

array_multisort($date, SORT_DESC, $cartList);

[bluejay002]

this one really works fine:

 

<?php
// given they have something like this
$data = array();

$data[] = array(0 => 67, 1 => 2);
$data[] = array(0 => 86, 1 => ;
$data[] = array(0 => 85, 1 => 6);
$data[] = array(0 => 98, 1 => 2);
$data[] = array(0 => 86, 1 => 6);
$data[] = array(0 => 67, 1 => 7);

// Obtain a list of columns
foreach ($data as $key => $row) {
    $volume[$key]  = $row[0];
    $edition[$key] = $row[1];
}

// Sort the data with volume descending, edition ascending
// Add $data as the last parameter, to sort by the common key
array_multisort($volume, SORT_DESC, SORT_REGULAR, $edition, SORT_ASC, $data);

print_r($data);
?>

 

may i know the structure of your array?

[millercj]

<?PHP
$cartList[$i] [0] = $nextresult['name'];
$cartList[$i] [1] = $nextresult['price'];
$cartList[$i] [2] = $nextresult['QTY'];
$cartList[$i] [3] = $nextresult['sizeDesc'];
$cartList[$i] [4] = $nextresult['image'];
$cartList[$i] [5] = $nextresult['date'];
?>

[bluejay002]

so I presume you can d o something like this:

 

<?php
// all other code... given $resource is the result of mysql_query()
$cartList = array();

while($nextresult = mysql_fetch_assoc($resource)) {
    $car = array();

    $car[0] = $nextresult['name'];
    $car[1] = $nextresult['price'];
    $car[2] = $nextresult['QTY'];
    $car[3] = $nextresult['sizeDesc'];
    $car[4] = $nextresult['image'];
    $car[5] = $nextresult['date'];

    $cartList[] = $car;
}

foreach($cartList as $key => $row) {
    $name[$key]  = $row[0];
    $price[$key] = $row[1];
    $qty[$key]  = $row[2];
    $sizedesc[$key] = $row[3];
    $image[$key]  = $row[4];
    $date[$key] = $row[5];
}

array_multisort($date, SORT_DESC, SORT_REGULAR, $cartList);?>

 

one question though, you are sorting it by date right? I don't think it is really necessary to sort it again.

 

And I think the problem you had is because you are sorting it with date... which I guess you need to make a custom one for that... except you add another field of date which is in unix timestamp and sort it with that as numeric. Apart from that, I still suggest not to sort it in PHP since you can sort it in SQL with date and knowing that changing the title doesn't really matter much with that, since you said you want to sort it with the sixth column.