Using two enums in Swift - swift

Question

I have two enums Items and Filters as
enum Items: Int {
case ItemA = 0,
ItemB,
ItemC,
ItemD,
ItemE
}
enum Filters: Int {
case FilterA = 0,
FilterB
}
I need to have the Items enum to be in Int.
And I am trying to implement Filters enum so that:
Filters(0).filter() returns [ItemA, ItemB]
Filters(1).filter() returns [ItemC, ItemD, ItemE]
Filters(0).count() returns 2
Filters(1).count() returns 3
Enums in swift is so much different than how I know enums from C... Can't get a grasp. Thanks!

Answer 1

There are several errors and bad practices in your code.
An enum name must be sigular
An enum case name should begin with a lowercase letter
An enum case name should not contain the name of the enum itself (eg. a instead of ItemA)
The filter and count methods IMO should be added to the Item enum
The filter and count methods should receive a Filter value, not an Int
You are free to manually assign 0 to the first case but this is not needed because the compiler will do it for you
IMO Condition is a better name for the Filter enum
Solution
Here's my solution
enum Condition: Int {
case a, b
}
enum Item: Int {
case a, b, c, d, e
static func filter(with condition: Condition) -> [Item] {
switch condition {
case .a: return [.a, .b]
case .b: return [.c, .d, .e]
}
}
static func count(with condition: Condition) -> Int {
return filter(with: condition).count
}
}
Usage
Item.filter(with: .a) // [a, b]
Item.filter(with: .b) // [c, d, e]
Item.count(with: .a) // 2
Item.count(with: .b) // 3

Answer 2

I hope that you can find this useful:
enum Items: Int {
case ItemA = 0,
ItemB,
ItemC,
ItemD,
ItemE
}
enum Filters: Int {
case FilterA = 0,
FilterB
func items() -> [Items]? {
switch self {
case .FilterA:
return [Items.ItemA, Items.ItemB]
case .FilterB:
return [Items.ItemC]
}
return nil
}
func count() -> Int {
return items()?.count ?? 0
}
}
let filter = Filters.FilterA
filter.items()
filter.count()
you can instantiate filter enum like this also:
let filter = Filters(rawValue: 0)
FYI swift cases should start with lowercase by the book, I left them uppercased to do not creat more confusions compare to your question code snippet.

Answer 3

Since this looks like static data a simple solution would be to keep the different sets of enum elements in a dictionary. And I agree with another poster that the naming of your enum could be better
enum Item: Int {
case a, b, c, d, e
}
let itemFilter = [0: [Item.a, Item.b]],
[1: [Item.c, Item.d, Item.e]]
if let filter = itemFilter[0] {
print(filter)
print(filter.count)
}