Sort array in swiftui by multiple conditions - swift

Question

how it is possible to sort an array by multiple conditions.
struct UserInformationModel: Identifiable, Hashable {
let id = UUID()
var isVip: Bool
let userIsMale: Bool
let userName: String
let age: Int
let userCountry: String
let countryIsoCode: String
let uid: String
}
And the view model contain the code:
class GetUserInformationViewModel: ObservableObject {
#Published var allUsers = [UserInformationModel]()
fun sortmyarray(){
self.allUsers = self.allUsers.sorted(by: {$0.isVip && !$1.isVip})
}
how its possible to sort first the vip users, and then sort by age and then country?

Answer 1

Here is a simple way to sort on multiple properties (I have assumed a sort order here for each property since it isn't mentioned in the question)
let sorted = users.sorted {
if $0.isVip == $1.isVip {
if $0.age == $1.age {
return $0.userCountry < $1.userCountry
} else {
return $0.age < $1.age
}
}
return $0.isVip && !$1.isVip
}
If the above is the natural sort order for the type then you could let the type implement Comparable and implement the < func
struct UserInformationModel: Identifiable, Hashable, Comparable {
//properties removed for brevity
static func < (lhs: UserInformationModel, rhs: UserInformationModel) -> Bool {
if lhs.isVip == rhs.isVip {
if lhs.age == rhs.age {
return lhs.userCountry < rhs.userCountry
} else {
return lhs.age < rhs.age
}
}
return lhs.isVip && !rhs.isVip
}
}
and then the sorting would be
let sorted = users.sorted()

Answer 2

Use tuples.
allUsers.sorted {
($1.isVip.comparable, $0.age, $0.userCountry)
<
($0.isVip.comparable, $1.age, $1.userCountry)
}
public extension Bool {
/// A way to compare `Bool`s.
///
/// Note: `false` is "less than" `true`.
enum Comparable: CaseIterable, Swift.Comparable {
case `false`, `true`
}
/// Make a `Bool` `Comparable`, with `false` being "less than" `true`.
var comparable: Comparable { .init(booleanLiteral: self) }
}
extension Bool.Comparable: ExpressibleByBooleanLiteral {
public init(booleanLiteral value: Bool) {
self = value ? .true : .false
}
}