Online PHP editor | refs for 2mWEk

<?php $strings = [ "a1a2a3a4aaaa", "a3333aaaaaaa", "a1a2a3aaaaa2", "a1a2a3", "a222", "aaaa", "a2aa", "f2fdfgdd", "w333rrrrrrr4", "rrrrrrrr4444", "r22rrrrrrrrr", "g4fff333ffff", "333333333333", "1111", "1aaa", "1aaaaaaaaaaa", "1a2aaaaaaaaa", "a1aaaaaaaaaaa", "a11111aaaaaa", "a122a3aaaaa2", "a1a2a3a4a5aa" ]; $pattern = "/^[a-z](?=(?:[a-z]*\d){0,4}(?![a-z]*\d))(?=[a-z\d]{3,11}$)[a-z\d]+$/"; foreach ($strings as $string) { echo $string . " ==> " . preg_match($pattern, $string) . PHP_EOL; }