- Output for 7.0.0 - 7.0.20, 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
- Warning: preg_match(): Unknown modifier 'g' in /in/6Aj8F on line 3
<?php
echo preg_match('/^[a-z]{2}-[A-Z]{2}$/g', 'en-US');