Online PHP editor | output for SRSpN

<?php $tests = [ ['word' => 'example', 'mask' => 'lmp'], // true ['word' => 'goodness', 'mask' => 'dns'], // false ['word' => 'slippers', 'mask' => 'eip'], // true ['word' => 'slippers', 'mask' => 'ips'], // false ['word' => 'google', 'mask' => 'go'], // true ['word' => 'food', 'mask' => 'go'], // false ['word' => 'bananas', 'mask' => 'ans'], // true ['word' => 'candle', 'mask' => 'ace'], // false ['word' => 'mississippi', 'mask' => 'i'], // true ['word' => 'executive', 'mask' => 'ecitx'], // false ]; foreach ($tests as ['word' => $word, 'mask' => $mask]) { var_export([ $word, $mask, preg_match_all("/[$mask]+/", $word, $m) && array_filter($m[0], fn($chars) => !ltrim($mask, $chars)), preg_match_all("/[$mask]{" . strlen($mask) . ",}/", $word, $m) && array_filter($m[0], fn($chars) => !ltrim($mask, $chars)), // preg_replace('/[a-z]/', "(?=[$mask]*$0)", $mask), (bool) preg_match('/' . preg_replace('/[a-z]/', "(?=[$mask]*$0)", $mask) . "[$mask]+/", $word) ]); echo "\n---\n"; }