- var_dump: documentation ( source)
- array_merge: documentation ( source)
<?php
$one=['A','B','C'];
$two=['D','E'];
var_dump($one+$two);
echo '---------------------';
var_dump($two+$one);
echo '---------------------';
var_dump(array_merge($one,$two));
echo '---------------------';
var_dump(array_merge($two,$one));