3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = "<b>ayat</b><br /><b>ollah</b>"; echo $str; $str = preg_replace( "/</u", "/ </u", $str ); echo $str; ?>
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, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 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
<b>ayat</b><br /><b>ollah</b>/ </ub>ayat/ </u/b>/ </ubr />/ </ub>ollah/ </u/b>

preferences:
250.14 ms | 406 KiB | 395 Q