Sort Multidimentional Array in PHP according a part of an array

Question

I have the following array:

items = array(
        'note' => array(),
        'text' => array(),
        'year' => array()
        )

So I have:

[note] => Array
(
   [0] => 'note1'
   [1] => 'note2'
   [2] => 'note3'
), 
[text] => Array
(
   [0] => 'text1'
   [1] => 'text2'
   [2] => 'test3'
), 
[year] => Array
(
   [0] => '2002'
   [1] => '2000'
   [2] => '2011'
)

And I would like to arrange the above arrays by year. but when moving elements I would like to move the corresponding elements in other arrays(note,text).

For example:

[note] => Array
(
   [2] => 'note3'
   [0] => 'note1'
   [1] => 'note2'
), 
[text] => Array
(
   [2] => 'text3'
   [0] => 'text1'
   [1] => 'test2'
), 
[year] => Array
(
   [2] => '2011'
   [0] => '2002'
   [1] => '2000'
)

Answer 1

I would first extract the year part and sort it by value, while still maintaining the key, using arsort():

$yearData = $array['year'];
arsort($yearData);//sort high-to-low by value, while maintain it's key.

Finally, sort the data using this newly sorted year:

$newArray['note'] = array();
$newArray['text'] = array();
$newArray['year'] = array();

foreach($yearData as $key => $value){
    $newArray['note'][$key] = $array['note'][$key];
    $newArray['text'][$key] = $array['text'][$key];
    $newArray['year'][$key] = $array['year'][$key];
}

FYI, there are a bunch of functions that deal with sorting arrays in PHP.

Answer 2

I think a better organization to your array would be something like this:

[0] => Array(
    'note' => note1, 'text' => 'text1', 'year' => '2002)
[1] => Array(
    'note' => note2, 'text' => 'text2', 'year' => '2000)
[2] => Array(
    'note' => note3, 'text' => 'text4', 'year' => '2011)

This way, each related item stays together and it's easier to sort them by the desired type.

$items = array(
    array(
        'note' => value,
        'text' => value,
        'year' => value
        ),
    array(
        'note' => value,
        'text' => value,
        'year' => value
        )
    )