数组不相等但实际上是？

Question

这太疯狂了。我正在比较自定义类型的两个数组，但它说它不相等但实际上是，因为我打印了其中的所有对象并用 https://www.diffchecker.com 检查它们是否不同，但它们不相等！我正在使用 Swift 4.2

func deleteFavorite(_ favorite: Favorite) {
var oldFavorites = getFavoriteSurahs()

oldFavorites.forEach {
    [=10=].reciter.surahs.forEach {
        print([=10=].name)
        print([=10=].number)
    }
    print()

    favorite.reciter.surahs.forEach {
        print([=10=].name)
        print([=10=].number)
    }

    print(NSArray(array:
        [=10=].reciter.surahs).isEqual(favorite.reciter.surahs))
    // It prints false BUT IT SHOULD PRINT TRUE, BECAUSE THEY'RE ACTUALLY EQUAL
}
}

那是我的古兰经 class:

class Surah: NSObject, NSCoding {
private(set) public var name: String
private(set) public var number: Int

init(number: Int, name: String) {
    self.number = number
    self.name = name
}

func encode(with aCoder: NSCoder) {
    aCoder.encode(self.name, forKey: "name")
    aCoder.encode(self.number, forKey: "number")
}

required init?(coder aDecoder: NSCoder) {
    self.name = aDecoder.decodeObject(forKey: "name") as! String
    self.number = aDecoder.decodeInteger(forKey: "number")
}
}

这是我的 getFavoriteSurahs() 函数：

func getFavoriteSurahs() -> [Favorite] {
    if let favoritesData = self.object(forKey: UD_FAVORITES) as? Data {
        do {
            let favorites = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(favoritesData) as! [Favorite]
            return favorites
        } catch {
            debugPrint(error)
            return [Favorite]()
        }
    } else {
        print("EMPTY Favorites")
        return [Favorite]()
    }
}

UPDATE This is so dump:

        print([=13=].surah.number == favorite.surah.number)
        print([=13=].surah.name == favorite.surah.name)
// Prints true

        print([=13=].surah == favorite.surah)
// Prints false

UPDATE 2

if [=14=].reciter.name == favorite.reciter.name && [=14=].reciter.image == favorite.reciter.image && [=14=].reciter.documentID == favorite.reciter.documentID &&
            [=14=].reciter.surahs.count == favorite.reciter.surahs.count &&

            [=14=].surah.number == favorite.surah.number &&
            [=14=].surah.name == favorite.surah.name {
            print("OMG FINALLY")
        } else {
            print("NOO NOO NOO")
        }

// Prints OMG FINALLY. After checking every single item. Is this normal??

Answer 1

NSArray 是引用类型，因此您正在检查两个 NSArray 指针是否相等。您应该使用本机 Swift Array 类型，它可以满足您的需求。

Answer 2

如果您将 NSArray 的 isEqual 用于自定义对象（不是来自 SDK），那么您需要为该类型的对象实现 isEqual。类似的东西：

override func isEqual(object: AnyObject?) -> Bool {
        if let object = object as? MyClass {
       // check for every ivar that should be equal
            return foo == object.foo && bar == object.bar
        } else {
            return false
        }
    }

Answer 3

您正在子类化 NSObject，它实现了 Equatable 协议，但默认情况下仅使用指针相等性。您需要覆盖 isEqual(_:) 方法和 hash 属性:

override func isEqual(_ object: Any?) -> Bool {
    guard let rhs = object as? Surah else { return false }
    return number == rhs.number && name == rhs.name
}

override var hash: Int {
    return number.hashValue ^ name.hashValue
}

let s1 = Surah(number: 1, name: "One")
let s2 = Surah(number: 1, name: "One")
s1 == s2       // => true
[s1] == [s2]   // => true

数组不相等但实际上是？

Array is not equal but it actually is?

arrays

iphone

xcode

ios

swift4.2