3v4l.org

run code in 300+ PHP versions simultaneously
<?php $phones = [ '00491384004924', '0491384004924', '491384004924', ]; foreach ($phones as $phone) { $phone = preg_replace('/^0{0,2}49/', '0', $phone); echo $phone, PHP_EOL; }

preferences:
48.51 ms | 1245 KiB | 5 Q