How can I get values using key in Carbon Fields from Multiselect?

One of the Carbon Fields developers here.

Thank you for your feedback!

Currently, the Carbon Fields stores only the keys and they don’t have a built-in method to retrieve the selected values from the options array.

You can pass a callable which returns an array with the options as an argument to the add_options method.

function available_options() {
    return array(
        'windows' => 'Windows',
        'mac' => 'Mac OS/ OSX',
        'linux' => 'Linux',
        'android' => 'Android',
        'mobile' => 'Mobile',
        'tv' => 'Smart TV',
        'desktop' => 'Desktop',
        'router' => 'Router',
        'raspberrypi' => 'Raspberry Pi',
    );
}


Field::make( 'multiselect', 'available_on', 'Available on' )
    ->add_options( 'available_options' ),

Then use the function when you want to retrieve the correct values from the stored keys:

$all_options = available_options();
$available_on = carbon_get_post_meta( $post_id, 'available_on' );

foreach ( $available_on as $option_key ) {
    echo $all_options[ $option_key ];
}