3v4l.org

run code in 300+ PHP versions simultaneously
<?php /*echo preg_replace_callback('/([a-z]+)(_[a-z]+)/', function($u) { var_dump($u); return ucwords(str_replace('_', '', $u[1])); } , 'rob_tr_yuui'); */ echo preg_replace('/([a-z]+)(_[a-z]+)/', '$1.$2', 'rob_tr_yuui');
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.17 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
rob._tr_yuui
preferences:
250.79 ms | 406 KiB | 341 Q