So i need to return the number (6, 8 or 10) with the country value.
 So in the example, with 'sweden' its supposed to return 8 but the key of the array is apparently just Array(). Is the wrong  in the structure of my array or the usage of array_keys?
$list= array (
  'list' => 
  array (
    6 => 
    array (
        'default',
        'finland'
    ),
    8 => 
    array (
        'sweden',
        'norway'
    ),
    10 => 
    array (
        'germany',
        'belgia'
    ),
  ),
);
print_r(array_keys($list, "sweden"));
return: Array()
 
     
     
    
