3v4l.org

run code in 300+ PHP versions simultaneously
<?php $order = isset( $_GET['o'] ) ? '?o='.$_GET['o'].'&p=' : '?p='; echo "<a href='$order.1'>1</a> ";
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.6 - 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 - 8.2.19, 8.3.0 - 8.3.7
<a href='?p=.1'>1</a>

preferences:
110.86 ms | 404 KiB | 203 Q