- var_dump: documentation ( source)
- array_merge: documentation ( source)
- array_unique: documentation ( source)
<?php
$a = array(1,2,3);
$b = array(1,2,3);
$f = array(array(2),3,4);
$c = array(array_merge($a, $b, $f));
$d = array_unique($c);
var_dump($d);