3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = 'foo the moo moo cow not the moo cow is the cow the moo cow is the cow not the moo cow bar'; print $str; print preg_replace('/(\b.*\b)\1/', '', $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 - 5.6.40, 7.0.0 - 7.0.33, 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
foo the moo moo cow not the moo cow is the cow the moo cow is the cow not the moo cow barfoo the cow not not the moo cow bar

preferences:
304.94 ms | 406 KiB | 453 Q