Online PHP editor | refs for B8KVU

<?php $lines = [ "need 4 speed", "4 speed", "speed 4", "4speed", "speed4", "speed2car" ]; foreach ($lines as $line) { $pattern = "~^\d+\h+|\h+\d+$|(\h+\d+\h+)~"; echo preg_replace_callback($pattern, function($matches){ return array_key_exists(1, $matches) ? " " : ""; }, $line) . PHP_EOL; }