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