Смешанные домены Как навести определенный порядок?

Question

СЛУЧАЙНЫЙ СПИСОК ДОМЕНОВ:

$DOMAIN_ARRAY = [
    'mydomain.com',
    'hair.mydomain.com',
    'web.developer.yoursite.com',
    'game.yoursite.com',
    'yoursite.com',
    'good.mydomain.com',
    'great.yoursite.com',
    'test.page.mydomain.com',
    'check.yoursite.com',
    'test.mydomain.com'
];

ЖЕЛАЕМЫЙ РЕЗУЛЬТАТ:

mydomain.com

• test.page.mydomain.com

• hair.mydomain.com

• good.mydomain.com

• test.mydomain.com

yoursite.com

• web.developer.yoursite.com

• game.yoursite.com

• great.yoursite.com

• check.yoursite.com

    <?php       
    $URL = "ide.geeksforgeeks.org";    
   $arr = preg_split('[\.]', $URL);     
   $subdomain = $arr[0];      
   echo $subdomain;
  

Answer 1

<?php

$domains = [
    'mydomain.com',
    'hair.mydomain.com',
    'web.developer.yoursite.com',
    'game.yoursite.com',
    'yoursite.com',
    'good.mydomain.com',
    'great.yoursite.com',
    'test.page.mydomain.com',
    'check.yoursite.com',
    'test.mydomain.com'
];

function domainsFirst($a, $b)
{   
    if ($a == $b) {
      return 0;
    }
    return (substr_count($a, '.') < substr_count($b, '.')) ? -1 : 1;
}

// Sorts the array by main domains first
usort($domains, "domainsFirst");

$result = [];

foreach ($domains as $domain){
    // Main domain
    if (substr_count($domain, '.') == 1){
        if (!isset($result[$domain])){
            $result[$domain] = [];
        }
    } else { // Subdomain
        $sub = explode('.', $domain);
        // Discover the main domain by taking the two last indexes
        $key = $sub[count($sub) - 2]. '.' .$sub[count($sub) - 1];
        $result[$key][] = $domain;
    }
}

print_r($result);

Выходы

Array
(
    [yoursite.com] => Array
        (
            [0] => check.yoursite.com
            [1] => great.yoursite.com
            [2] => game.yoursite.com
            [3] => web.developer.yoursite.com
        )

    [mydomain.com] => Array
        (
            [0] => test.mydomain.com
            [1] => good.mydomain.com
            [2] => hair.mydomain.com
            [3] => test.page.mydomain.com
        )

)

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