3v4l.org

run code in 300+ PHP versions simultaneously
<?php $extra = array('adgroup', 'campaign', 'content', 'source', 'term', 'mobile', 'tablet'); print_r(array_merge($extra, $extra));
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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.7
Array ( [0] => adgroup [1] => campaign [2] => content [3] => source [4] => term [5] => mobile [6] => tablet [7] => adgroup [8] => campaign [9] => content [10] => source [11] => term [12] => mobile [13] => tablet )

preferences:
275.33 ms | 406 KiB | 460 Q