How to sort a multi-array

benton · 07-15-2008, 01:33 AM

I have an array like this

PHP Code:


			
 Array

(

    [1] => Array

        (

            [52] => Milk Chocolate

            [221] => Vanilla Bean

            [212] => Banana Cream

            [80] => Chocolate Peanut Butter

        )



)

I need to have it sorted on the value. The only examples I can find for doing this are those using multisort but that resets the keys, which won't work in this case. I tried using usort with a callback function like this but it failed.

PHP Code:


			
function cmp($a, $b)

{

    if ($a == $b) {

        return 0;

    }

    return ($a < $b) ? -1 : 1;

}

foreach ($myarray as $sub)

 $myarray[$sub] = usort($sub, cmp);

Would someone please point out my mistake or how best to do this?

drewbee · 07-15-2008, 03:51 AM

I believe asort is what your looking for.

PHP Code:


			
$array = array('1' => array('52' => 'Milk Choclate',
                            '221' => 'Vanilla Bean',
                            '212' => 'Banana Cream',
                            '80' => 'Choclate Peanut Butter'));

asort($array['1']);
echo print_r($array);

I am not to sure if this is exactly what you are looking for. If you could provide a more accurate example as if I were to build a recursive function for this (multi-dim array);

It would need to start at the deepest array and work back to the beginning (what string value does an array have?) if you see what I mean.

abiko · 07-15-2008, 11:42 AM

From where do you get your array? Database or somewhere else?
Can you provide more info?

benton · 07-15-2008, 12:10 PM

Quote:

Originally Posted by drewbee

I believe asort is what your looking for.

PHP Code:


			
$array = array('1' => array('52' => 'Milk Choclate',

                            '221' => 'Vanilla Bean',

                            '212' => 'Banana Cream',

                            '80' => 'Choclate Peanut Butter'));



asort($array['1']);

echo print_r($array);

I am not to sure if this is exactly what you are looking for. If you could provide a more accurate example as if I were to build a recursive function for this (multi-dim array);

It would need to start at the deepest array and work back to the beginning (what string value does an array have?) if you see what I mean.

I don't understand what you mean by "what string value..." but I added the following based on what you said and it works great. But it doesn't do it backwards so I'm wondering if it OK to use?

PHP Code:


			
         for ($i = 0; $i < count($myarray); ++$i)

         {

           if (is_array($myarray[$i]))

             asort($myarray[$i]);

         }

benton · 07-15-2008, 12:15 PM

Quote:

Originally Posted by abiko

From where do you get your array? Database or somewhere else?
Can you provide more info?

The array is generated dynamically from data read from a database but controlled by items not part of the database. So the array can end up like

PHP Code:


			
 Array

(

    [1] => Array

        (

            [212] => Banana Cream

            [80] => Chocolate Peanut Butter

            [52] => Milk Chocolate

            [221] => Vanilla Bean

        )



    [3] => Array

        (

            [45] => Alpine Punch

            [194] => Apricot

        )



)

So there may be ten items read in from the database but, in the above example, only items 1 and 3 will be added to the array. Then the key and value of each array element is loaded from the database data for that item.

abiko · 07-15-2008, 12:32 PM

Is this a solution to your problems?

PHP Code:


			
<?php

$array = array(   '1' =>  array(  '21'  =>  'Item 1',
                                  '928' =>  'Item what!?!',
                                  '86'  =>  'Too late item',
                                  '153' =>  'What is happening here?!?'

                                ),
                  '2' =>  array(  '997' =>  'Fruit - apple', 
                                  '77' => 'Another fruit - orange',
                                  '4'   =>  'The icky fruit',
                                  '64'  =>  'Watermelon'
                                )
                );
                
/*
 *  Sort the items
 */
 
 foreach ( $array as $row => $data) {
      ksort( $data);
      $_compile[$row] =  $data;
 
 } 
 
 /*
  * output
  */
  
  echo "<h1>First array</h1>";
  print_r ( $array);
  
  echo "<h1>The compiled array</h1>";
  print_r( $_compile );                  
      

?>

Output

Code:

Array
(
    [1] => Array
        (
            [21] => Item 1
            [86] => Too late item
            [153] => What is happening here?!?
            [928] => Item what!?!
        )

    [2] => Array
        (
            [4] => The icky fruit
            [64] => Watermelon
            [77] => Another fruit - orange
            [997] => Fruit - apple
        )

)

benton · 07-15-2008, 01:16 PM

No, that doesn't work. What does $_compile[$row] represent? I tried inserting the array name there but it didn't work either. The code I posted does seem to work. Is there anything wrong with using a for loop?

drewbee · 07-15-2008, 02:50 PM

Hi Benton,

So what I understand is that you will have a key index housing a sub-array.

So what you gave will work perfectly fine.

PHP Code:


			
         for ($i = 0; $i < count($myarray); ++$i) 
         { 
           if (is_array($myarray[$i])) 
             asort($myarray[$i]); 
         }

You do not need to go backwards with this; I thought you actually needed to traverse (crawl down) the array.

benton · 07-15-2008, 04:24 PM

Thanks for letting me know. I've tried a bunch of tests and it seems to work fine. Thanks for providing the code to make it work.