Question

这太疯狂了。我正在比较两个自定义类型的数组，但它表示不相等，但实际上是相等的，因为我在其中打印了所有对象，并用https://www.diffchecker.com检查了它们是否不同，是否相同！我正在使用Swift 4.2

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

oldFavorites.forEach {
    $0.reciter.surahs.forEach {
        print($0.name)
        print($0.number)
    }
    print()

    favorite.reciter.surahs.forEach {
        print($0.name)
        print($0.number)
    }

    print(NSArray(array:
        $0.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》课：

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]()
    }
}

更新     这是如此转储：

        print($0.surah.number == favorite.surah.number)
        print($0.surah.name == favorite.surah.name)
// Prints true

        print($0.surah == favorite.surah)
// Prints false

更新2

if $0.reciter.name == favorite.reciter.name && $0.reciter.image == favorite.reciter.image && $0.reciter.documentID == favorite.reciter.documentID &&
            $0.reciter.surahs.count == favorite.reciter.surahs.count &&

            $0.surah.number == favorite.surah.number &&
            $0.surah.name == favorite.surah.name {
            print("OMG FINALLY")
        } else {
            print("NOO NOO NOO")
        }

//最终打印OMG。检查每个项目后。这正常吗？

Answer 1

您要为实现NSObject协议的Equatable子类化，但默认情况下仅使用指针相等。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

Answer 2

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

Answer 3

如果将NSArray的 isEqual 用于自定义对象（不是来自SDK），则需要为该类型的对象实现isEqual。像这样：

    //Make the service call:
    let obs = this.httpClient.request(method, url, options);
    //Return the observable:
    return obs;

数组不相等，但实际上是相等吗？

3 个答案: