swift - 如何在 Swift 中按名字按字母顺序排列数组？

Question

这是我当前的模型类代码。

final class ContactData
{
    static let sharedInstance = ContactData()

    private var contactList : [Contact] =
            [Contact(name:"Mike Smith",email:"mike@smith.com"),
             Contact(name:"John Doe",email:"john@doe.com"),
             Contact(name:"Jane Doe",email:"jane@doe.com")]


    private init()
    {
        // SORTING HERE
    }

    var index = 0

    func newContact(new:Contact)
    {
        contactList.append(new)
        //sort
    }

    func updateContact(updated:Contact)
    {
        contactList[index]=updated
        //sort
    }

    func  previousContact() -> Contact
    {
        index-=1
        if index < 0
        {
            index = contactList.count-1
        }
        return contactList[index]
    }

    func nextContact() -> Contact
    {
        index+=1
        if index == contactList.count
        {
            index = 0
        }
        return contactList[index]
    }

    func firstContact() -> Contact
    {
        return contactList[0]
    }

    func currentContact() -> Contact
    {
        return contactList[index]
    }
}

一切都运行正常，但我尝试使用以下方法按字母顺序排列 Contact 数组:

var sortedContacts = contactList.sorted{
            $0.localizedCaseinsensitiveCompare($1)==ComparisonResult.orderedAscending}
        }

但是我得到一个错误:

Value of type 'Contact' has no member 'localizedCaseinsensitiveCompare'

浏览这里的问题，我只能找到按字母顺序排列数组的唯一方法。

我正在运行 Swift 3 和 Xcode 8.3

Answer 1

你应该让你的类 Contact 符合 Comparable 协议(protocol):

class Contact: Comparable, CustomStringConvertible {
    let name: String
    let email: String
    init(name: String, email: String) {
        self.name = name
        self.email = email
    }
    var description: String {
        return name + " - " + email
    }
    // provide your custom comparison
    static func <(lhs: Contact, rhs: Contact) -> Bool {
        return lhs.name.localizedCaseInsensitiveCompare(rhs.name)   == .orderedAscending ||
               lhs.email.localizedCaseInsensitiveCompare(rhs.email) == .orderedAscending
    }
    // you will need also to make it conform to Equatable
    static func ==(lhs: Contact, rhs: Contact) -> Bool {
        return lhs.name == rhs.name && lhs.email == rhs.email
    }
}

---

Playground 测试

let c1 = Contact(name:"Mike Smith",email:"mike@smith.com")
let c2 = Contact(name:"John Doe",email:"john1@doe.com")
let c3 = Contact(name:"John Doe",email:"john2@doe.com")
let c4 = Contact(name:"Jane Doe",email:"jane2@doe.com")
let c5 = Contact(name:"Jane Doe",email:"jane1@doe.com")

let people = [c1, c2, c3, c4, c5]
print(people)   // "[Mike Smith - mike@smith.com, John Doe - john1@doe.com, John Doe - john2@doe.com, Jane Doe - jane2@doe.com, Jane Doe - jane1@doe.com]\n"
print(people.sorted())  // "[Jane Doe - jane1@doe.com, Jane Doe - jane2@doe.com, John Doe - john1@doe.com, John Doe - john2@doe.com, Mike Smith - mike@smith.com]\n"