3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = array(); $a[] = 1; $a[] = 2; $a[] = 3; $a[] = 1; $a[] = 1; $a[] = 2; $a[] = 4; $acount = array_count_values($a); var_dump(array_keys($acount));
based on EnHUT
Output for 4.3.0 - 7.2.0
array(4) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(4) }