How do I create a Set of custom objects (Swift)?

Question

For my iOS app I have a model something like

class Person {
    var Id: Int
    var Name: String

    init(id: Int, name: String?) {
        self.Id = id
        self.Name = name ?? ""
    }
}

Then later on in my ViewController when I load data from the server I add some people to an array

class ViewController: UIViewController {
    var people:[Person] = []

    override func viewDidLoad() {
        self.loadPeople()
    }

    func loadPeople() {
        // This data will be coming from a server request
        // so is just sample. It could have users which 
        // already exist in the people array

        self.people.append(Person(id: "1", name: "Josh"))
        self.people.append(Person(id: "2", name: "Ben"))
        self.people.append(Person(id: "3", name: "Adam"))
    }
}

What I am now trying todo is turn the people array into a Set<Person> so it will not add duplicates. Is this possible to do or do I need to change my logic?

Answer 1

To make set of Person you need to make it conform to Equatable and Hashable protocols:

class Person: Equatable, Hashable {
    var Id: Int
    var Name: String

    init(id: Int, name: String?) {
        self.Id = id
        self.Name = name ?? ""
    }

    var hashValue: Int {
        get {
            return Id.hashValue << 15 + Name.hashValue
        }
    }
}

func ==(lhs: Person, rhs: Person) -> Bool {
    return lhs.Id == rhs.Id && lhs.Name == rhs.Name
}

Then you can use set of persons like this:

var set = Set<Person>()
set.insert(Person(id: 1, name: "name"))