Напиши метод, считающий факториал числа. Что такое факториал — функция, определённая на множестве неотрицательных целых чисел. Так, факториал числа 5: 5! = 5 4 3 2 1
0! = 1
(-n) = NaN
enum fError: Error {
case .ferror
}
func factorial(_ number: Int) -> throws Int {
if number < 0 {
throw error
}
var result: Int = 1
for item in 1...number {
result = item * result
}
return result
}
struct Awesome {
var name: String
init(name: String) {
self.name = name
}
}
let obj1 = Awesome(name: "123")
let obj2 = Awesome(name: "456")
let array1 = [obj1, obj2]
let array2 = array1
array2[0].name = "000"
print(array1[0].name) // 123
class Service {
func getData(completion: @escaping (String) -> Void) {
DispatchQueue.main.asyncAfter(deadline: .now() + 20.0) {
completion("hello world")
}
}
}
class ViewController: UIViewController {
let service = Service()
let label = UILabel()
override func viewDidLoad() {
super.viewDidLoad()
service.getData { (data) in
self.label.text = data
}
}
}
class MyViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
print(2)
DispatchQueue.main.async {
print(3)
DispatchQueue.main.async { print(5) }
print(4)
}
print(6)
}
}
let vc = MyViewController()
print(1)
vc.view
print(7)
//// 1 2 6 7 3 4 5
final class Tracker {
private init() {}
static let shared = Tracker()
func track(event: String) {
print("Event (event)")
}
}
// MARK: - Наш код
final class Analytics {
func trackScreen() {
Tracker.shared.track(event: "Screen")
}
}