- var_dump: documentation ( source)
- print_r: documentation ( source)
- array_change_key_case: documentation ( source)
<?php
$automerken = array("bmw" => "1 Series", "Mercedes" => "A klasse");
var_dump($automerken);
print_r(array_change_key_case($automerken, CASE_UPPER));
print_r(array_change_key_case($automerken, CASE_LOWER));