3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = array( 'a'=>1, 'b'=>2, 'c'=>3 ); $b = array( 'b'=>3, 'c'=>4, 'd'=>5 ); foreach(array_keys($a + $b) as $key){ echo $key; }
Output for 4.3.0 - 7.2.0
abcd