3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = ''; for ($i = 30000; $i > 0; $i--) { $str .= 'String concatenation. '; }
Output for 7.0.0 - 7.0.27, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
preferences:
155.2 ms | 407 KiB | 5 Q