Posted by Jochem Maas on 03/09/05 09:26

Gabino Travassos wrote:
> Hello List
>
> I've looked at array_multisort( ), but it doesn't seem like the right
> function. Here's an example of my array, it's a listing of CD reviews:
> $cds=array(array("Lowest of the Low", 20050105,9,"Toronto"),
> array("Heavy Blinkers",20041020,6,"Chicago"),
> array("Apple,Fiona",20050308,5,"Seattle"));
>
> If I wanted to sort them alphabetically, no problem, just sort($cds).

does that even work? sort() sorts the values but the values are all arrays,
how does php determine the correct order of a set of arrays?

> If I want to sort them by date (the second item in the array) or by
> ranking (the third), how do I do that?
>
> Is there something simple?

here is a class I knocked up to order a simple multi-dimensional array....
its not the be all and end all but hopefully its useful to you (maybe you learn something new)

examples are at the bottom:

<?php
/**
* MDASort.class.php :: simple interface to sort a mutlidimensional array
*
* We often have arrays of arrays where the sub-arrays are rows of data
* (either created or extracted from a database) - this class allows us to
* easily sort arrays in the base container array by any number of keys found
* in the sub-arrays. be aware that it is assumed that the array keys found in the
* sub arrays are associative. Also maybe the _sortcmp method could be enhanced to
* allow arbitrary levels of arrays to be sorted: by calling sort() on a level
* N array also the sortKeys contents would then have to be checked to see if
* they applied to the current (sub-)array
*
* @author Some guy on PHP comment board. <http://php.net/manual/en/function.usort.php>
* @author Jochem Maas <jochem@iamjochem.com>
*/

/**
* This file and its contents is not copyrighted;
* The contents are free to be used by anybody under any conditions.
*/

class MDASort {

private $dataArray; //the array we want to sort.
private $sortKeys; //the order in which we want the array to be sorted.

function __construct()
{
if ($cnt = func_num_args()) {
$args = func_get_args();
if (isset($args[0])) {
$this->setData($args[0]);
}
if (isset($args[1])) {
$this->setSortKeys($args[1]);
}
if (isset($args[2]) && $args[2] === true) {
$this->sort();
}
}
}

function _sortcmp($a, $b, $i=0)
{
$r = strnatcmp($a[$this->sortKeys[$i][0]],$b[$this->sortKeys[$i][0]]);
if ($this->sortKeys[$i][1] == "DESC") $r = $r * -1;
if($r==0) {
$i++;
if ($this->sortKeys[$i]) $r = $this->_sortcmp($a, $b, $i);
}
return $r;
}

function sort()
{
if(count($this->sortKeys)) {
usort($this->dataArray, array($this,"_sortcmp"));
}
}

function setData($dataArray = array())
{
$this->dataArray = $dataArray;
}

function setSortKeys($sortKeys = array())
{
$this->sortKeys = $sortKeys;
}

function getData()
{
return $this->dataArray;
}

function getSortKeys()
{
return $this->sortKeys;
}
}

/* example of usage */
/*

$sorter = new MDASort;
$sorter->setData( array(
array("name" => "hank", "headsize" => "small", "age" => 32),
array("name" => "sade", "headsize" => "petit", "age" => 36),
array("name" => "hank", "headsize" => "large", "age" => 33),
array("name" => "sade", "headsize" => "large", "age" => 32),
array("name" => "john", "headsize" => "large", "age" => 32),
array("name" => "hank", "headsize" => "small", "age" => 36),
array("name" => "hank", "headsize" => "small", "age" => 40)
));

$sorter->setSortKeys( array(
array('name','ASC'),
array('headsize','DESC'),
array('age','ASC'),
));

$sorter->sort();
$sortedArray = $sorter->getData();

*/

/* 2nd example of usage */
/*

$data = array(
array("name" => "hank", "headsize" => "small", "age" => 32),
array("name" => "sade", "headsize" => "petit", "age" => 36),
array("name" => "hank", "headsize" => "large", "age" => 33),
array("name" => "sade", "headsize" => "large", "age" => 32),
array("name" => "john", "headsize" => "large", "age" => 32),
array("name" => "hank", "headsize" => "small", "age" => 36),
array("name" => "hank", "headsize" => "small", "age" => 40)
);

$sort = array(
array('name','ASC'),
array('headsize','DESC'),
array('age','ASC'),
);

$sorter = new MDASort($data, $sort);
$sorter->sort();
$sortedArray = $sorter->getData();

*/

/* 3rd example of usage */
/*

$data = array(
array("name" => "hank", "headsize" => "small", "age" => 32),
array("name" => "sade", "headsize" => "petit", "age" => 36),
array("name" => "hank", "headsize" => "large", "age" => 33),
array("name" => "sade", "headsize" => "large", "age" => 32),
array("name" => "john", "headsize" => "large", "age" => 32),
array("name" => "hank", "headsize" => "small", "age" => 36),
array("name" => "hank", "headsize" => "small", "age" => 40)
);

$sort = array(
array('name','ASC'),
array('headsize','DESC'),
array('age','ASC'),
);

$sorter = new MDASort($data, $sort, true); // auto sort
$sortedArray = $sorter->getData();

*/

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