sorting three dimensional array of stdclass objects in php

Question

i'm having a problem sorting that array, i've tried few different methods of usort but nothing seems to be working. i want to order it by "vieworder". to print it i used the array_values() function this is the array:

 Array
(
    [0] => Array
        (
            [0] => stdClass Object
                (
                    [name] => 1.png
                    [size] => 673478
                    [url] => files/1.png
                    [thumbnailUrl] => files/thumbnail/1.png
                    [deleteUrl] => uploads/index.php?file=1.png&_method=DELETE
                    [deleteType] => POST
                    [id] => 17
                    [type] => image/png
                    [title] => test
                    [vieworder] => 1
                )

            [1] => stdClass Object
                (
                    [name] => 10.png
                    [size] => 151629
                    [url] => files/10.png
                    [thumbnailUrl] => files/thumbnail/10.png
                    [deleteUrl] => uploads/index.php?file=10.png&_method=DELETE
                    [deleteType] => POST
                    [id] => 16
                    [type] => image/png
                    [title] => test10
                    [vieworder] => 10
                )

            [2] => stdClass Object
                (
                    [name] => 11.png
                    [size] => 682790
                    [url] => files/11.png
                    [thumbnailUrl] => files/thumbnail/11.png
                    [deleteUrl] => uploads/index.php?file=11.png&_method=DELETE
                    [deleteType] => POST
                    [id] => 18
                    [type] => image/png
                    [title] => test
                    [vieworder] => 5
                )

            [3] => stdClass Object
                (
                    [name] => 2.png
                    [size] => 118038
                    [url] => files/2.png
                    [thumbnailUrl] => files/thumbnail/2.png
                    [deleteUrl] => uploads/index.php?file=2.png&_method=DELETE
                    [deleteType] => POST
                    [id] => 15
                    [type] => image/png
                    [title] => test2
                    [vieworder] => 2
                )

            [4] => stdClass Object
                (
                    [name] => 5.png
                    [size] => 496543
                    [url] => files/5.png
                    [thumbnailUrl] => files/thumbnail/5.png
                    [deleteUrl] => uploads/index.php?file=5.png&_method=DELETE
                    [deleteType] => POST
                    [id] => 14
                    [type] => image/png
                    [title] => test2
                    [vieworder] => 2
                )

        )

)

thanks!

Answer 1

Assuming your data structure like this:

$std_one = new stdClass();
$std_one->id = 3;
$std_one->name = 123;
$std_one->vieworder = 13;

$std_two = new stdClass();
$std_two->id = 1;
$std_two->name = 4;
$std_two->vieworder = 1;

$std_three = new stdClass();
$std_three->id = 1;
$std_three->name = 4;
$std_three->vieworder = 2;

$std_four = new stdClass();
$std_four->id = 1;
$std_four->name = 4;
$std_four->vieworder = 3;

// Data array which needs to be sorted according to vieworder property.
$data[0][] = $std_one; 
$data[0][] = $std_two;
$data[0][] = $std_three;
$data[0][] = $std_four;

// Passing $data[0] variable in to our callback function sortStdClass
usort($data[0],'sortStdClass');

// Finally sortStdClass callback function

function sortStdClass($a, $b){
   return $a->vieworder > $b->vieworder; // Sort in ASC order
}

// Print $data;
echo '<pre>'.print_r($data,1).'</pre>';
// Prints:
    Array
(
    [0] => Array
        (
            [0] => stdClass Object
                (
                    [id] => 1
                    [name] => 4
                    [vieworder] => 1
                )

            [1] => stdClass Object
                (
                    [id] => 1
                    [name] => 4
                    [vieworder] => 2
                )

            [2] => stdClass Object
                (
                    [id] => 1
                    [name] => 4
                    [vieworder] => 3
                )

            [3] => stdClass Object
                (
                    [id] => 1
                    [name] => 4
                    [vieworder] => 10
                )

        )

)

Answer 2

update: i've finally figured it out: because the calling to the usort function is from inside a class the usort method should be private static and the calling should contain this.

usort($content[0], array($this, "sortStdClass"));

private static function sortStdClass($a, $b){
    return $a->vieworder > $b->vieworder; // Sort in ASC order
}