如何创建一组自定义对象（Swift）？

Posted 2021-04-14

对于我的ios应用程序，我有一个类似的模型

class Person {
    var Id: Int
    var Name: String

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

然后在我的ViewController中，当我从服务器加载数据时，我将一些人添加到数组中

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"))
    }
}

我现在尝试todo是将people阵列变成Set<Person>所以它不会添加重复。这是可能做的还是我需要改变我的逻辑？

答案

要制作一组Person，您需要使其符合Equatable和Hashable协议：

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
}

然后你可以像这样使用一组人：

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

另一答案

使用Swift 2.0，Hashable和Equitable是NSObject的一部分。您需要做的就是为感兴趣的属性覆盖“isEqual”和“var hash：”。在这种情况下：“Id”，Set将排除具有相同ID的Person对象。

    class Person: NSObject {
        var Id: Int
        var Name: String

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

        override var hash: Int {
        return Id.hashValue
   }

        override func isEqual(object: AnyObject?) -> Bool {
            guard let rhs = object as? Person else {
                return false
            }
            let lhs = self

            return lhs.Id == rhs.Id
        }


    }

          func mergeArrays(){
       let person1 = Person(id: 1, name: "Tom")
       let person2 = Person (id: 2, name: "John")
       let person3 = Person(id: 3, name: "Adam")


       let downloadedPeople  = [person1,person2] //[{NSObject, Id 1, Name "Tom"}, {NSObject, Id 2, Name "John"}] 

       let peopleStoredLocally = [person1,person3] //[{NSObject, Id 1, Name "Tom"}, {NSObject, Id 3, Name "Adam"}]

       let downloadedPeopleSet = Set(downloadedPeople) //{{NSObject, Id 2, Name "John"}, {NSObject, Id 1, Name "Tom"}}


       let mergedSet = downloadedPeopleSet.union(peopleStoredLocally) //{{NSObject, Id 2, Name "John"}, {NSObject, Id 3, Name "Adam"}, {NSObject, Id 1, Name "Tom"}}


       let mergedArray = Array(mergedSet)//[{NSObject, Id 2, Name "John"}, {NSObject, Id 3, Name "Adam"}, {NSObject, Id 1, Name "Tom"}]

    }