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  1. <?php
  2. $hostnames = [
  3. 	'sub1.hostname1.com',
  4. 	'sub12.hostname2.com',
  5. 	'suboo2.hostname3.com',
  6. 	'sub2.hostname4.com'];
  7.  
  8. $filtered = array_filter($hostnames, function($hostname) {
  9.     // assume that the "subdomain" is the first hostname segment, separated by "."
  10.     list($subdomain, $theRest) = explode('.', $hostname, 2);
  11.  
  12.     return preg_match_all('/1|2/', $subdomain) === 1;
  13. });
  14.  
  15. print_r($filtered);
Success #stdin #stdout 0.01s 20568KB
comments (?)
stdin 
Standard input is empty
stdout 
Array
(
    [0] => sub1.hostname1.com
    [2] => suboo2.hostname3.com
    [3] => sub2.hostname4.com
)
https://ideone.com/MwbS7T
language:
PHP (php 7.3.5)
created:
10 years ago
visibility:
public

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