func saveObjectID(_ object: NSManagedObject) {
    let objectID = object.objectID.uriRepresentation().absoluteString
    UserDefaults.standard.set(objectID, forKey: "savedObjectID")
}

func fetchSavedObjectID(context: NSManagedObjectContext) -> NSManagedObject? {
    guard let objectIDString = UserDefaults.standard.string(forKey: "savedObjectID"),
          let objectURL = URL(string: objectIDString) else { return nil }

    let objectID = context.persistentStoreCoordinator?.managedObjectID(forURIRepresentation: objectURL)

    if let objectID = objectID {
        return context.object(with: objectID)
    }
    return nil
}

import Foundation

class SafeCounter {
    private var value = 0
    private let lock = NSLock()

    func increment() {
        lock.lock()        // Захват мьютекса
        value += 1
        lock.unlock()      // Освобождение мьютекса
    }

    func getValue() -> Int {
        lock.lock()        // Захват мьютекса
        let currentValue = value
        lock.unlock()      // Освобождение мьютекса
        return currentValue
    }
}

let counter = SafeCounter()
DispatchQueue.global().async {
    for _ in 0..<1000 {
        counter.increment()
    }
}

DispatchQueue.global().async {
    for _ in 0..<1000 {
        counter.increment()
    }
}

// Подождём немного, чтобы дать потокам закончить работу
Thread.sleep(forTimeInterval: 1)
print("Final counter value: \(counter.getValue())")

UIView.animate(withDuration: 0.5) {
    self.button.frame.origin.x += 100
}

let button = UIButton(type: .system)
button.frame = CGRect(x: 50, y: 100, width: 200, height: 50)
button.setTitle("Нажми меня", for: .normal)
view.addSubview(button)

let borderLayer = CALayer()
borderLayer.frame = CGRect(x: 0, y: 0, width: 100, height: 100)
borderLayer.borderWidth = 2
borderLayer.borderColor = UIColor.red.cgColor
view.layer.addSublayer(borderLayer)

RunLoop.current.run(mode: .default, before: Date.distantFuture)     

     let timer = Timer(timeInterval: 1.0, repeats: true) { _ in
         print("Timer fired!")
     }
     RunLoop.current.add(timer, forMode: .default)

import Foundation

class Example {
    var timer: Timer?

    func startRunLoop() {
        timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerFired), userInfo: nil, repeats: true)
        RunLoop.current.run()
    }

    @objc func timerFired() {
        print("Timer fired!")
    }
}

let example = Example()
example.startRunLoop()

class Person {
    var pet: Pet?
}

class Pet {
    var owner: Person?
}

let person = Person()
let pet = Pet()

person.pet = pet
pet.owner = person // Теперь оба объекта держат друг друга, и ARC их не удалит

class Pet {
    weak var owner: Person? // Теперь утечки памяти не будет
}

func printDouble(value: Double) {
    print("Значение: \(value)")
}

printDouble(value: printDouble) // Ошибка: Несовместимые типы

func processDouble(_ value: Double, action: (Double) -> Void) {
    action(value)
}

processDouble(42.0, action: printDouble) // Выведет: "Значение: 42.0"

   var array = [1, 2, 3, 4, 5]
   var set: Set = [1, 2, 3, 4, 5]
   var dictionary = ["one": 1, "two": 2, "three": 3]
   

   var name: String? = "John"
   if let unwrappedName = name {
       print("Name is \(unwrappedName)")
   }
   

   func increment(value: inout Int) {
       value += 1
   }
   var number = 1
   increment(value: &number)
   

   DispatchQueue.global(qos: .background).async {
       // Фоновая задача
       DispatchQueue.main.async {
           // Обновление UI на главном потоке
       }
   }
   

   class MyClass {
       lazy var expensiveObject: ExpensiveObject = {
           return ExpensiveObject()
       }()
   }
   

   var cache = [Int: Int]()
   func fibonacci(_ n: Int) -> Int {
       if let result = cache[n] {
           return result
       }
       if n <= 1 { return n }
       let result = fibonacci(n - 1) + fibonacci(n - 2)
       cache[n] = result
       return result
   }
   

   for i in 0..<1000 {
       // Оптимизированный код
   }
   

   struct Point {
       var x: Int
       var y: Int
   }