- array_map: documentation ( source)
- var_dump: documentation ( source)
- array_values: documentation ( source)
<?php
$names = array(
'device' => 'Phones',
'tablet' => 'Tablets',
'smartwatch' => 'Smartwatch',
'speaker' => 'Speaker',
'headphones' => 'Headphones',
'wearable' => 'Wearable',
);
var_dump(array_map(strtoupper, array_values($names)));