Displaying the number of updates available in the Admin area

Here’s an example of the data returned from the wp_get_update_data() function:

Array
(
    [counts] => Array
        (
            [plugins] => 3
            [themes] => 2
            [wordpress] => 0
            [translations] => 0
            [total] => 5
        )

    Displaying the number of updates available in the Admin area => 3 Plugin Updates, 2 Theme Updates
)

So the number of available plugin updates should be available with:

// Number of available plugin updates:
$update_data = wp_get_update_data();
echo $update_data['counts']['plugins'];

Update:

To display the following plugin info in the admin area:

There are available updates for 3 plugins out of 22

we can additionally use the get_plugins() function:

if ( ! function_exists( 'get_plugins' ) )
{
    require_once ABSPATH . 'wp-admin/includes/plugin.php';
}

$data = array( 
    'updates'   =>  $update_data['counts']['plugins'],
    'total'     =>  count( get_plugins() ),
);

printf( 
    "There are available updates for <strong>%d</strong> plugins  
     out of <strong>%d</strong>",
    $data['updates'],
    $data['total']
);

We can add more info, in a similar way, with get_mu_plugins() and get_dropins().