将嵌套字典保存为UserDefaults并管理重复检查[Swift 4.2]

// 嵌套字典
let nestedDictionary: [String: Any] = [
    "key1": "value1",
    "key2": 2,
    "key3": [
        "nestedKey1": "nestedValue1",
        "nestedKey2": "nestedValue2"
    ]
]

// 将嵌套字典转换为NSData
if let data = try? NSKeyedArchiver.archivedData(withRootObject: nestedDictionary, requiringSecureCoding: false) {
    // 将NSData保存到UserDefaults
    UserDefaults.standard.set(data, forKey: "nestedDictionary")
}

// 从UserDefaults中读取NSData
if let data = UserDefaults.standard.data(forKey: "nestedDictionary") {
    // 将NSData转换回嵌套字典
    if let dictionary = try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? [String: Any] {
        // 检查嵌套字典中的重复项
        var uniqueValues: Set<AnyHashable> = []
        var hasDuplicates = false
        
        for (_, value) in dictionary {
            if uniqueValues.contains(where: { $0 as? AnyHashable == value as? AnyHashable }) {
                hasDuplicates = true
                break
            } else {
                uniqueValues.insert(value)
            }
        }
        
        if hasDuplicates {
            print("嵌套字典中存在重复项")
        } else {
            print("嵌套字典中没有重复项")
        }
    }
}