PHP：数组int比较错误？

I don't know why I cannot get the expected result. The result shows 2 > 10 > 1 but I want 10 > 2 > 1 Can anyone help me? Thanks

<?
function reorder($a, $b)
    {
        $a = substr($a, strlen("a/"));
        $a = substr($a, 0, -strlen(".php"));
        $b = substr($b, strlen("a/"));
        $b = substr($b, 0, -strlen(".php"));
        switch ($a) {
            case "1m_microUSB_cable":
                $a['order'] = 1;
                break;
            case "25cm_microUSB_cable":
                $a['order'] = 2;
                break;
            case "30cm_lightning_cable":
                $a['order'] = 3;
                break;
            case "1.5m_lightning_cable":
                $a['order'] = 5;
                break;
            case "1m_lightning_cable":
                $a['order'] = 4;
                break;
            case "1m_microUSB_upgrade_cable":
                $a['order'] = 6;
                break;
            case "hand_ring_cable_Android":
                $a['order'] = 7;
                break;
            case "hand_ring_cable_Apple":
                $a['order'] = 8;
                break;
            case "Light_bulb_key_ring":
                $a['order'] = 9;
                break;
            case "candy_machine":
                $a['order'] = 10;
                break;
            default:
                $a['order'] = 999;
            }
        switch ($b) {
            case "1m_microUSB_cable":
                $b['order'] = 1;
                break;
            case "25cm_microUSB_cable":
                $b['order'] = 2;
                break;
            case "30cm_lightning_cable":
                $b['order'] = 3;
                break;
            case "1.5m_lightning_cable":
                $b['order'] = 5;
                break;
            case "1m_lightning_cable":
                $b['order'] = 4;
                break;
            case "1m_microUSB_upgrade_cable":
                $b['order'] = 6;
                break;
            case "hand_ring_cable_Android":
                $b['order'] = 7;
                break;
            case "hand_ring_cable_Apple":
                $b['order'] = 8;
                break;
            case "Light_bulb_key_ring":
                $b['order'] = 9;
                break;
            case "candy_machine":
                $b['order'] = 10;
                break;
            default:
                $b['order'] = 999;
            }

        if ($a['order'] == $b['order']) {
            return 0;
        } elseif ($a['order'] > $b['order']) {
            return -1;
        } else {
            return 1;
        }
    }
?>

I want to reorder the array and I use

$glob = glob("a/*.php");
include ("reorder.php");
usort($glob, "reorder");
foreach ($glob as $filename) {
        include ($filename);
        include ("templates/a.php");
    }

The dump of $glob:

array ( 0 => 'a/Light_bulb_key_ring.php', 1 => 'a/hand_ring_cable_Apple.php', 2 => 'a/hand_ring_cable_Android.php', 3 => 'a/1m_microUSB_upgrade_cable.php', 4 => 'a/1.5m_lightning_cable.php', 5 => 'a/1m_lightning_cable.php', 6 => 'a/30cm_lightning_cable.php', 7 => 'a/25cm_microUSB_cable.php', 8 => 'a/candy_machine.php', 9 => 'a/1m_microUSB_cable.php', )

I reorder the array from 1 to 9 is ok but when there is order 10, the order 10 will be after the order 1 but not the order 9. I don't know why? I hope someone can help me. Thank you! Sorry for my poor English.

I am so sorry that I type it unclearly. Therefore, I create a image.

The order now: Image 1

The expected order: Image 2

The given result is a lexical order, not a numeric order. To force numeric order, change:

    $aNum = intval($a['order']);
    $bNum = intval($b['order']);

    return $bNum - $aNum;

I don't quite understand your sorting function logic. Any filename with value other then "test0", "test1" and "test2" will have same highest order "999".

If all of your filenames have "test<[\d]+>.php" format then you can simply extract that value and use that for the comparison:

function reorder($a, $b)
{
    if (preg_match('|/a/test(\d+).php|', $a, $match)) {
        $a = (int) $match[1];
    } else {
        $a = 999; // Filename is in different format so place it at the end of the list         
    }
    if (preg_match('|/a/test(\d+).php|', $b, $match)) {
        $b = (int) $match[1];
    } else {            
        $b = 999;
    }

    return $a - $b;
}

$files = Array('/a/extra.php', '/a/test0.php', '/a/test1.php', '/a/test5.php', '/a/test10.php', '/a/test11.php', '/a/test100.php', '/a/test22.php',);
usort($files, 'reorder');
var_dump($files);

This ouputs:

array(8) {
  [0]=>
  string(12) "/a/test0.php"
  [1]=>
  string(12) "/a/test1.php"
  [2]=>
  string(12) "/a/test5.php"
  [3]=>
  string(13) "/a/test10.php"
  [4]=>
  string(13) "/a/test11.php"
  [5]=>
  string(13) "/a/test22.php"
  [6]=>
  string(14) "/a/test100.php"
  [7]=>
  string(11) "/a/extra.php"
}

Finally, I found the answer. It is a very silly mistake.

I would like to say thank you to all of the people who help me here. Thanks!

$a['order'] and $b['order'] is not work properly because the $a and $b are string (with content). As a result, $a['order'] will change the first letter(/digit) of the string $a. ($b same problem)

For example, $a = "this_is_string" will be replaced to $a = "2his_is_string" if $a['order'] = 2. So, if $a['order'] = 10 (any two or more digits), $a will become "1his_is_string" and the order will be 1 but not 10. Therefore, this error occurred.

To solve this problem, just change all $a['order'] to $a_order (or any other variables) and $b['order'] to $b_order (or any other variables).

(Sorry for my poor English)