Sorting multidimensional arrays

[Anon]

Hi there!

I know this topic has been delt with many times before, but I just can't get the sorting to work. I have this array containing name and points of a 8 different teams. I want to sort the whole array by using the points... The array is built up like this (not the actual code of course, it's how the arrays end up looking):

$points = array();

$points[1][0] = 5; // TEAM 1 has 5 points
$points[1][1] = "Brazil"; // THE NAME OF TEAM 1
...
...
...
$points[8][0] = 10; // TEAM 8 has 10 points
$points[8][1] = "Germany"; // THE NAME OF TEAM1 1

Now, I want to sort the whole $points-array based on $points[$i][0]-field.

Plz, don't just give me the name of the functions I should use, I can't get them to work properly. I would be really greatful if someone could give me a working example...

Any help is appreciated!
Vasse

[sp0rk]

Pretty much straight from the manuals entry for usort. I'm not sure if this was what you're after, but at least it's something to play with.

$points[0][0] = 5;
$points[0][1] = "Brazil";
$points[1][0] = 7;
$points[1][1] = "England";
$points[2][0] = 12;
$points[2][1] = "Sweden";
$points[3][0] = 10;
$points[3][1] = "Germany";

function cmp($a, $b) {
if($a == $b) return 0;
return ($a > $b) ? -1 : 1;
}
usort($points, "cmp");

print_r($points);

[Anon]

Execute this sample and see for yourself:

<?

$Pn = array();

$Pn[0][1] = 30;
$Pn[0][0] = "This is number 30";

$Pn[1][1] = 20;
$Pn[1][0] = "This is number 20";

$Pn[2][1] = 50;
$Pn[2][0] = "This is number 50";

$Pn[3][1] = 35;
$Pn[3][0] = "This is number 35";

sort($Pn);

for($i=0;$i<1;$i++){
for($n=0;$n<4;$n++){
echo $Pn[$n][$i]."<BR>";
}
}

$Pn2 = array();

$Pn2[0][0] = 30;
$Pn2[0][1] = "This is number 30";

$Pn2[1][0] = 20;
$Pn2[1][1] = "This is number 20";

$Pn2[2][0] = 50;
$Pn2[2][1] = "This is number 50";

$Pn2[3][0] = 35;
$Pn2[3][1] = "This is number 35";

sort($Pn2);

for($i=0;$i<1;$i++){
for($n=0;$n<4;$n++){
echo $Pn2[$n][$i]."<BR>";
}
}

?>

It looks like sort() orders the array based on the [$i][0] index, not by [$i][1] or else. Maybe this is what you're looking for...

Hope this helps

fLIPIS

[Anon]

Hi!
Thanks for the replies!

I've tried these solutions before, they both work at my own computer... but when I upload it to the webhost I get this error:

"Warning: cannot compare arrays or objects in..."

I don't what version of PHP they have got, but the rest of my scripts with some functions that were implemented late in PHP work just fine!

Is there maybe a custom function that someone has written that could help me out?

Thanks
Vasse

[Anon]

You can try uploading a script with this code on it:

<?
phpinfo();
?>

and get to know all about that PHP build. Maybe it's some obscure thing (these things happen in programming) :-)

Sorry it didn't work.

fLIPIS

[Anon]

Ok, the webhost is running PHP 4.0.0 on Apache, that's about all I can figure out based on the info 🙂

My server is on Win98 with IIS, PHP 4.1.2...

What else should I be looking for? Since I can't change anything in the php.ini it won't help anyways...

Thanks again,
Vasse

[Anon]

I found this function amongst the comments in the manual:

<?php // filename: qsort2.php
function array_qsort2 (&$array, $column=0, $order=SORT_ASC, $first=0,
$last= -2)
{
// $array - the array to be sorted
// $column - index (column) on which to sort
// can be a string if using an associative array
// $order - SORT_ASC (default) for ascending or SORT_DESC for descending
// $first - start index (row) for partial array sort
// $last - stop index (row) for partial array sort

if($last == (-2)) {
$last = count($array) - 1;
}
if($last > $first) {
$alpha = $first;
$omega = $last;
$guess = $array[$alpha][$column];
while($omega >= $alpha) {
if($order == SORT_ASC) {
while($array[$alpha][$column] < $guess) $alpha++;
while($array[$omega][$column] > $guess) $omega--;
} else {
while($array[$alpha][$column] > $guess) $alpha++;
while($array[$omega][$column] < $guess) $omega--;
}
if($alpha > $omega) break;
$temporary = $array[$alpha];
$array[$alpha++] = $array[$omega];
$array[$omega--] = $temporary;
}
array_qsort2 ($array, $column, $order, $first, $omega);
array_qsort2 ($array, $column, $order, $alpha, $last);
}
}
?>

Thanks for your help!
Vasse