3v4l.org

run code in 300+ PHP versions simultaneously
<?php $text = "ABC01 ABC02 ABC03 ABC04 ABC05 ABC06 "; echo preg_replace( '/.+\K\R+(?=ABC04)/', ' - ', trim($text) );
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
ABC01 ABC02 ABC03 - ABC04 ABC05 ABC06
preferences:
52.06 ms | 405 KiB | 63 Q