How to sort multiple arrays in PHP

Question

hi, i have wrote a script to produce an array of data but now want to display in order of score. The array outputs as follows;

[display_name] => Array
    (
        [0] => ACT_Web_Designs
        [1] => user1_design
        [2] => user2_design
    )

[proffesion] => Array
    (
        [0] => Web Developer
        [1] => web developer
        [2] => Web Developer
    )

[score] => Array
    (
        [0] => 15
        [1] => 6
        [2] => 15
    )

[img] => Array
    (
        [0] => ./?0000=gif&0001=3fadb8c362ff39f3322909899ff14760&0002=prof_pic
        [1] => 
        [2] => 
    )

so in a nutshell I am wanting it to be converted as follows;

    [display_name] => Array
    (
        [0] => ACT_Web_Designs
        [1] => user2_design
        [2] => user1_design
    )

[proffesion] => Array
    (
        [0] => Web Developer
        [1] => web developer
        [2] => Web Developer
    )

[score] => Array
    (
        [0] => 15
        [1] => 15
        [2] => 6
    )

[img] => Array
    (
        [0] => ./?0000=gif&0001=3fadb8c362ff39f3322909899ff14760&0002=prof_pic
        [1] => 
        [2] => 
    )

I have been looking at asort() but cant get anything to work. any help would be much appreciated.

Answer 1

Doesn't it work to just rsort the score array?

rsort($data['score'], SORT_NUMERIC);

Answer 2

I have managed to do this, i was just after a more efficient way;

$array = array(
            'display_name' => array(0 => 'ACT_Web_Designs', 1 => 'user1_design', 2 => 'user2_design' ),
            'proffesion' => array( 0 => 'Web Developer', 1 => 'web developer', 2 => 'Web Developer' ),
            'score' => array( 0 => 15, 1 => 6, 2 => 15 ),
            'img' => array( 0 => './?0000=gif&0001=3fadb8c362ff39f3322909899ff14760&0002=prof_pic', 1 => '', 2 => '' )
);

arsort($array['score'], SORT_NUMERIC );
foreach($array['score'] as $key => $val ) {
    $newarray['display_name'][] = $array['display_name'][$key];
    $newarray['proffesion'][] = $array['proffesion'][$key];
    $newarray['score'][] = $array['score'][$key];
    $newarray['img'][] = $array['img'][$key];
}

print_r($newarray);

returns

Array
(
    [display_name] => Array
        (
            [0] => ACT_Web_Designs
            [1] => user2_design
            [2] => user1_design
        )

    [proffesion] => Array
        (
            [0] => Web Developer
            [1] => Web Developer
            [2] => web developer
        )

    [score] => Array
        (
            [0] => 15
            [1] => 15
            [2] => 6
        )

    [img] => Array
        (
            [0] => ./?0000=gif&0001=3fadb8c362ff39f3322909899ff14760&0002=prof_pic
            [1] => 
            [2] => 
        )

)

Answer 3

This will not re-sort them for you, but it will let you go through them in the order you want. You can reassign them if you want, but I'd just use this for the output order.

Edit: This will not work, due to the possibility of non-unique key values. See Comments below, and learn from my mistake

$sort_order = $array['score'];
arsort($sort_order);
$sort_order = array_flip($sort_order);
foreach($sort_order as $key){
    echo $array['display_name'][$key].' - '.$array['score'][$key];
}

Answer 4

This is exactly where the PHP's array_multisort comes to use. It is a case where you want to sort many arrays based on the comparison happening in just one of them.

I've modified the array score to have distinct values.

<?php

$arr = array(
                'display_name' => array('ACT_Web_Designs','user1_design','user2_design'),
                'proffesion' => array('Web Developer','web developer','web developer'),
                'score' => array(12,6,15),
                'img' => array('./?0000=gif&0001=3fadb8c362ff39f3322909899ff14760&0002=prof_pic','','')
            );

var_dump($arr);
array_multisort($arr['score'], SORT_ASC, SORT_NUMERIC,
                $arr['display_name'],
                $arr['proffesion'],
                $arr['img']
                );
var_dump($arr);


?>

Here goes a working demo.

Answer 5

How about this simpler one

$arr = array("k"=>array("A","B","C"),"l"=>array(15,6,15),"n"=>array("k","l","n"));
array_multisort($arr["k"],SORT_NUMERIC,SORT_DESC,$arr["l"],$arr["n"]);
var_dump($arr);

Answer 6

Use rsort()

<?php
$fruits = array("lemon", "orange", "banana", "apple");
rsort($fruits);
reset($fruits);
while (list($key, $val) = each($fruits)) {
    echo "$key = $val\n";
}
?>  

This example would display:

0 = orange
1 = lemon
2 = banana
3 = apple

Answer 7

The most elegant solution that I could find would not reorder the data structure but merely access it in a different fashion.

$scores = $data['score'];
arsort($scores);
$keys_ordered_by_score = array_keys($scores);

Now you can, say, grab the display_name and "proffesion" that has the highest score by the following:

$first_place = $keys_ordered_by_score[0];
echo $data['display_name'][$first_place],
     ' is a ', $data['proffesion'][$first_place];

Of course, if you really need to reorder the data structure, this idea is useless to you. Any of the other answers using array_multisort() will likely suit that need.