3v4l.org

run code in 300+ PHP versions simultaneously
<?php $selected=array('11a_Ma1','11a_Sc2','11b_Ls1'); $already=array('11SJP','11a_Ma1','11a_Sc2'); print_r(array_diff($selected,$already)); print_r(array_diff($already,$selected)); $a1=array(1,2,3); $a2=array(1,2,3); $ad=array_diff($a1,$a2); if(isset($ad)){echo "YEAH";} if(!empty($ad)){echo "empty... bitch";}
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 - 8.3.6
Array ( [2] => 11b_Ls1 ) Array ( [0] => 11SJP ) YEAH
preferences:
262.5 ms | 406 KiB | 459 Q