3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php echo substr_replace('20140501', '01', 4, 2);
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.13.2, 7.0.0 - 7.1.0
20140101