Taking Swift Generics To The Extreme

In this presentation, we're starting from Swift Generics basic examples, and diving into how we, at monday.com, took this powerful Swift feature and used it to create awesome UI/UX behaviors with generic views all over the app.

Transcript

1. Taking Swift Generics To The Extreme 1 Ariel Pollack
2. !2
3. !3 280 Employees (TLV + NYC) 265,000 Weekly Active Paying Users 2.5x ARR (Annual Recurring Revenue) Every Year Top 10 Fastest Growing Private Companies in the World!
4. !4 The Board Item
5. !5 The Board Column
6. !6 Each column type have it’s own: • Appearance • Capabilities • Editing options • Integrations with other features in the platform
7. The mobile app should support all user’s data from the web (and more) !7
8. That’s easy with 7 column types !8
9. !9 But what about… 30 column types?!
10. And views… !10
11. And dashboard widgets… !11
12. We had to be able to scale fast without compromising performance and capabilities !12
13. Generics for the rescue! !13
14. Real life examples Popups !14
15. Real life examples Bottom Pickers !15
16. Real life examples Consistent Animations & Appearance !16
17. !17 29 years old ☀ Tel Aviv 7 years iOS dev 23 years computers geek Me and New Feature: a Dad :)
18. Me and !18 iOS Web 3.5 years ago
19. !19 Me and iOS Web Today :) Android
20. The Team !20 Amit Frishberg Android Eran Helft Product Manager Yuval Brand iOS Shani Frankel Design Sahar Weissman Android Yoni Levin Android Team Lead Nir Lachman iOS Ariel Pollack iOS Ronen Sabag Android
21. Agenda • Generics Basics • Generics and protocols - ❤ at first sight • Generic Views - how and why should you use it • Building a generic view! !21
22. “Generic programming is a style of computer programming in which algorithms are written in terms of types to-be-specified-later that are then instantiated when needed for specific types provided as parameters.” Generic Programming @ Wikipedia !22
23. public struct Array<Element> public func map<T>(_ transform: (Element) throws -> T) rethrows -> [T] open func decode<T>(_ type: T.Type, from data: Data) throws -> T where T : Decodable Foundations RxSwift public class Observable<Element> : ObservableType { public typealias E = Element } !23
24. Concept Array Element Use Case [“Hey”, “Man”] String Use Case [1, 2, 3] Int Use Case [CGRect.zero] CGRect Illustration: “Gentle Generics” by John Sundell !24
25. struct SimpleStorage { private var storedValues: [Int] = [] func getValues() -> [Int] { return self.storedValues } mutating func set(values: [Int]) { self.storedValues = values } } !25 Storing Numbers
26. struct SimpleStorage { private var storedValues: [Int] = [] func getValues() -> [Int] { return self.storedValues } mutating func set(values: [Int]) { self.storedValues = values } } !26 Storing Numbers
27. struct SimpleStorage { private var storedValues: [Int] = [] func getValues() -> [Int] { return self.storedValues } mutating func set(values: [Int]) { self.storedValues = values } } !27 Storing Numbers
28. struct SimpleStorage { private var storedValues: [Int] = [] func getValues() -> [Int] { return self.storedValues } mutating func set(values: [Int]) { self.storedValues = values } } !28 Storing Numbers
29. struct SimpleStorage { private var storedValues: [Int] = [] func getValues() -> [Int] { return self.storedValues } mutating func set(values: [Int]) { self.storedValues = values } } !29 Storing Numbers
30. struct SimpleStorage<T> { private var storedValues: [T] = [] func getValues() -> [T] { return self.storedValues } mutating func set(values: [T]) { self.storedValues = values } } !30 Storing Elements
31. struct SimpleStorage<T> { private var storedValues: [T] = [] func getValues() -> [T] { return self.storedValues } mutating func set(values: [T]) { self.storedValues = values } } !31 Storing Elements
32. Generics + Protocols = !32
33. protocol Storage { } Concept: Storing Data !33
34. protocol Storage { associatedtype T } Concept: Storing Data !34
35. protocol Storage { associatedtype T func getValues() -> [T] mutating func set(values: [T]) } Concept: Storing Data !35
36. protocol Storage { associatedtype T func getValues() -> [T] mutating func set(values: [T]) } Concept: Storing Data struct SimpleStorage<T> { // ... } !36
37. protocol Storage { associatedtype T func getValues() -> [T] mutating func set(values: [T]) } Concept: Storing Data struct SimpleStorage<T>: Storage { // ... } !37
38. protocol Storage { associatedtype T func getValues() -> [T] mutating func set(values: [T]) } Concept: Storing Data struct SimpleStorage<T>: Storage { // ... } !38
39. Use Cases: Local DB protocol DBSavable { ... } // Storing values to a local db class DBStorage<T>: Storage !39
40. Use Cases: Local DB protocol DBSavable { ... } // Storing values to a local db class DBStorage<T>: Storage where T: DBSavable { ... } !40
41. Use Cases: Local DB protocol DBSavable { ... } // Storing values to a local db class DBStorage<T>: Storage where T: DBSavable { ... } // An item that can be stored to a local db struct User: DBSavable { ... } !41
42. Use Cases: Local DB protocol DBSavable { ... } // Storing values to a local db class DBStorage<T>: Storage where T: DBSavable { ... } // An item that can be stored to a local db struct User: DBSavable { ... } // Subclass a defined generic type final class UsersDBStorage: DBStorage<User> { } !42
43. Use Cases: Local DB protocol DBSavable { ... } // Storing values to a local db class DBStorage<T>: Storage where T: DBSavable { ... } // An item that can be stored to a local db struct User: DBSavable { ... } // Subclass a defined generic type final class UsersDBStorage: DBStorage<User> { func someUsersSpecificMethod() { let values = getValues() // values: [User] } } !43
44. Use Cases: UserDefaults class UserDefaultsStorage<T> { where T: NSCoding { private let key: String private let userDefaults: UserDefaults init(key: String, userDefaults: UserDefaults = .standard) { self.key = key self.userDefaults = userDefaults } func getValues() -> [T] { guard let array = userDefaults.value(forKey: key) as? [T] else { return [] } return array } func set(values: [T]) { userDefaults.setValue(values, forKey: key) } } !44
45. Use Cases: UserDefaults class UserDefaultsStorage<T> { where T: NSCoding { private let key: String private let userDefaults: UserDefaults init(key: String, userDefaults: UserDefaults = .standard) { self.key = key self.userDefaults = userDefaults } func getValues() -> [T] { guard let array = userDefaults.value(forKey: key) as? [T] else { return [] } return array } func set(values: [T]) { userDefaults.setValue(values, forKey: key) } } !45
46. Use Cases: UserDefaults class UserDefaultsStorage<T>: Storage { where T: NSCoding { private let key: String private let userDefaults: UserDefaults init(key: String, userDefaults: UserDefaults = .standard) { self.key = key self.userDefaults = userDefaults } func getValues() -> [T] { guard let array = userDefaults.value(forKey: key) as? [T] else { return [] } return array } func set(values: [T]) { userDefaults.setValue(values, forKey: key) } } !46
47. Use Cases: UserDefaults class UserDefaultsStorage<T>: Storage { where T: NSCoding { private let key: String private let userDefaults: UserDefaults init(key: String, userDefaults: UserDefaults = .standard) { self.key = key self.userDefaults = userDefaults } func getValues() -> [T] { guard let array = userDefaults.value(forKey: key) as? [T] else { return [] } return array } func set(values: [T]) { userDefaults.setValue(values, forKey: key) } } !47
48. Use Cases: UserDefaults class UserDefaultsStorage<T>: Storage { where T: NSCoding { private let key: String private let userDefaults: UserDefaults init(key: String, userDefaults: UserDefaults = .standard) { self.key = key self.userDefaults = userDefaults } func getValues() -> [T] { guard let array = userDefaults.value(forKey: key) as? [T] else { return [] } return array } func set(values: [T]) { userDefaults.setValue(values, forKey: key) } } !48
49. Use Cases: UserDefaults class UserDefaultsStorage<T>: Storage where T: NSCoding { private let key: String private let userDefaults: UserDefaults init(key: String, userDefaults: UserDefaults = .standard) { self.key = key self.userDefaults = userDefaults } func getValues() -> [T] { guard let array = userDefaults.value(forKey: key) as? [T] else { return [] } return array } func set(values: [T]) { userDefaults.setValue(values, forKey: key) } } !49
50. Use Cases: UserDefaults Storing numbers to UserDefaults typealias NumbersStorage = UserDefaultsStorage<NSNumber> !50
51. Use Cases: UserDefaults Storing numbers to UserDefaults typealias NumbersStorage = UserDefaultsStorage<NSNumber> let visitedBoards = NumbersStorage(key: “visited_boards_ids”) !51
52. Use Cases: UserDefaults Storing numbers to UserDefaults typealias NumbersStorage = UserDefaultsStorage<NSNumber> let visitedBoards = NumbersStorage(key: “visited_boards_ids”) let boardIds = [1, 2, 3].map(NSNumber.init) visitedBoards.set(values: boardIds) visitedBoards.getValues() // => [1, 2, 3] !52
53. Generics + Protocols + UIKit = !53
54. <Generic Content> Generic View Containers I’m the title !54
55. protocol Configurable { associatedtype T func configure(with data: T) } typealias ConfigurableView = UIView & Configurable !55
56. class CardView<View>: ConfigurableView { where View: ConfigurableView { typealias Data = View.Data let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: Data) { containedView.configure(with: data) } } !56
57. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: T) { containedView.configure(with: data) } } !57
58. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: T) { containedView.configure(with: data) } } !58
59. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: T) { containedView.configure(with: data) } } !59 ConfigurableView ConfigurableView
60. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: T) { containedView.configure(with: data) } } !60 ConfigurableView ConfigurableView Data
61. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: T) { containedView.configure(with: data) } } !61 ConfigurableView ConfigurableView Data
62. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: T) { containedView.configure(with: data) } } !62
63. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle: UILabel = { let label = UILabel(frame: .zero) label.text = "I'm the title" return label }() // setup views somewhere… func configure(with data: T) { containedView.configure(with: data) } } !63
64. extension UILabel: Configurable { func configure(with text: String) { self.text = text } } !64
65. extension UILabel: Configurable { func configure(with text: String) { self.text = text } } !65
66. let labelCard = CardView<UILabel>() labelCard.configure(with: “Hello world!") extension UILabel: Configurable { func configure(with text: String) { self.text = text } } !66
67. let labelCard = CardView<UILabel>() labelCard.configure(with: “Hello world!") extension UILabel: Configurable { func configure(with text: String) { self.text = text } } !67
68. let labelCard = CardView<UILabel>() labelCard.configure(with: “Hello world!") extension UILabel: Configurable { func configure(with text: String) { self.text = text } } !68
69. extension UIImageView: Configurable { func configure(with image: UIImage) { self.image = image } } !69
70. extension UIImageView: Configurable { func configure(with image: UIImage) { self.image = image } } !70
71. let imageCard = CardView<UIImageView>() imageCard.configure(with: UIImage(named: “swift")!) extension UIImageView: Configurable { func configure(with image: UIImage) { self.image = image } } !71
72. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle = UILabel(frame: .zero) // called in init func setupViews() { ... } func configure(with data: T) { lblTitle.text = data.title containedView.configure(with: data) } } !72
73. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = View.T let containedView = View(frame: .zero) let lblTitle = UILabel(frame: .zero) // called in init func setupViews() { ... } func configure(with data: T) { lblTitle.text = data.title containedView.configure(with: data) } } !73
74. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = (title: String, data: View.T) let containedView = View(frame: .zero) let lblTitle = UILabel(frame: .zero) // called in init func setupViews() { ... } func configure(with data: T) { lblTitle.text = data.title containedView.configure(with: data.data) } } !74
75. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = (title: String, data: View.T) let containedView = View(frame: .zero) let lblTitle = UILabel(frame: .zero) // called in init func setupViews() { ... } func configure(with data: T) { lblTitle.text = data.title containedView.configure(with: data.data) } } !75
76. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = (title: String, data: View.T) let containedView = View(frame: .zero) let lblTitle = UILabel(frame: .zero) // called in init func setupViews() { ... } func configure(with data: T) { lblTitle.text = data.title containedView.configure(with: data.data) } } !76
77. class CardView<View>: ConfigurableView where View: ConfigurableView { typealias T = (title: String, data: View.T) let containedView = View(frame: .zero) let lblTitle = UILabel(frame: .zero) // called in init func setupViews() { ... } func configure(with data: T) { lblTitle.text = data.title containedView.configure(with: data.data) } } let imageCard = CardView<UIImageView>() imageCard.configure(with: ( title: "Image", data: UIImage(named: "swift")! )) !77
78. Real life examples Popups !78
79. !79 Let’s build a generic menu
80. Let’s build a generic menu • MenuView<OptionType> will present a list of options conforming to OptionType • Each option will have a title and an icon • It should be really easy to use !80
81. protocol MenuOption { var icon: UIImage { get } var title: String { get } } !81
82. protocol MenuOption { var icon: UIImage { get } var title: String { get } } !82 class MenuOptionCell: UITableViewCell, Configurable { let lblTitle = UILabel() let imgIcon = UIImageView() func setupViews() { ... } func configure(with option: MenuOption) { imgIcon.image = option.icon lblTitle.text = option.title } }
83. protocol MenuOption { var icon: UIImage { get } var title: String { get } } !83 class MenuOptionCell: UITableViewCell, Configurable { let lblTitle = UILabel() let imgIcon = UIImageView() func setupViews() { ... } func configure(with option: MenuOption) { imgIcon.image = option.icon lblTitle.text = option.title } }
84. class MenuView<OptionType> { UITableViewDataSource, UITableViewDelegate where OptionType: MenuOption { typealias SelectOptionClosure = (OptionType) -> Void // vars private var didSelectOption: SelectOptionClosure private var options: [OptionType] { didSet { tableView.reloadData() } } // views private lazy var tableView: UITableView = { ... }() init(didSelectOption: @escaping SelectOptionClosure) { ... } func configure(with options: [OptionType]) { self.options = options } // MARK: UITableViewDataSource & UITableViewDelegate // ... } !84
85. class MenuView<OptionType>: ConfigurableView { UITableViewDataSource, UITableViewDelegate where OptionType: MenuOption { typealias SelectOptionClosure = (OptionType) -> Void // vars private var didSelectOption: SelectOptionClosure private var options: [OptionType] { didSet { tableView.reloadData() } } // views private lazy var tableView: UITableView = { ... }() init(didSelectOption: @escaping SelectOptionClosure) { ... } func configure(with options: [OptionType]) { self.options = options } // MARK: UITableViewDataSource & UITableViewDelegate // ... } !85 typealias T = [OptionType]
86. class MenuView<OptionType>: ConfigurableView, UITableViewDataSource, UITableViewDelegate { where OptionType: MenuOption { typealias SelectOptionClosure = (OptionType) -> Void // vars private var didSelectOption: SelectOptionClosure private var options: [OptionType] { didSet { tableView.reloadData() } } // views private lazy var tableView: UITableView = { ... }() init(didSelectOption: @escaping SelectOptionClosure) { ... } func configure(with options: [OptionType]) { self.options = options } // MARK: UITableViewDataSource & UITableViewDelegate // ... } !86
87. class MenuView<OptionType>: ConfigurableView, UITableViewDataSource, UITableViewDelegate { where OptionType: MenuOption { typealias SelectOptionClosure = (OptionType) -> Void // vars private var didSelectOption: SelectOptionClosure private var options: [OptionType] { didSet { tableView.reloadData() } } // views private lazy var tableView: UITableView = { ... }() init(didSelectOption: @escaping SelectOptionClosure) { ... } func configure(with options: [OptionType]) { self.options = options } // MARK: UITableViewDataSource & UITableViewDelegate // ... } !87
88. class MenuView<OptionType>: ConfigurableView, UITableViewDataSource, UITableViewDelegate { where OptionType: MenuOption { typealias SelectOptionClosure = (OptionType) -> Void // vars private var didSelectOption: SelectOptionClosure private var options: [OptionType] { didSet { tableView.reloadData() } } // views private lazy var tableView: UITableView = { ... }() init(didSelectOption: @escaping SelectOptionClosure) { ... } func configure(with options: [OptionType]) { self.options = options } // MARK: UITableViewDataSource & UITableViewDelegate // ... } !88
89. class MenuView<OptionType>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionType: MenuOption { typealias SelectOptionClosure = (OptionType) -> Void // vars private var didSelectOption: SelectOptionClosure private var options: [OptionType] { didSet { tableView.reloadData() } } // views private lazy var tableView: UITableView = { ... }() init(didSelectOption: @escaping SelectOptionClosure) { ... } func configure(with options: [OptionType]) { self.options = options } // MARK: UITableViewDataSource & UITableViewDelegate // ... } !89
90. Use Case: Board Menu enum BoardMenuOption { case delete case rename } !90
91. Use Case: Board Menu enum BoardMenuOption { case delete case rename } extension BoardMenuOption: MenuOption { var title: String { switch self { case .delete: return “Delete" case .rename: return "Rename" } } var icon: UIImage { switch self { case .delete: return UIImage(named: “trash") case .rename: return UIImage(named: “rename") } } } !91
92. typealias BoardMenu = MenuView<BoardMenuOption> !92
93. let menuView = BoardMenu(didSelectOption: { option in print(option) }) typealias BoardMenu = MenuView<BoardMenuOption> !93
94. menuView.configure(options: [.rename, .delete]) typealias BoardMenu = MenuView<BoardMenuOption> let menuView = BoardMenu(didSelectOption: { option in print(option) }) !94
95. With a little refactor, we can make it work with different types of cells. !95
96. typealias ConfigurableCell = UITableViewCell & Configurable !96
97. class MenuView<OptionType>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionType: MenuOption { // ... } typealias ConfigurableCell = UITableViewCell & Configurable !97
98. class MenuView<OptionType>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionType: MenuOption { // ... } typealias ConfigurableCell = UITableViewCell & Configurable !98
99. class MenuView<OptionCell>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionCell: ConfigurableCell { typealias OptionType = OptionCell.Data // ... } typealias ConfigurableCell = UITableViewCell & Configurable !99
100. class MenuView<OptionCell>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionCell: ConfigurableCell { typealias OptionType = OptionCell.T // ... } typealias ConfigurableCell = UITableViewCell & Configurable !100
101. class MenuView<OptionCell>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionCell: ConfigurableCell { typealias OptionType = OptionCell.T // ... } typealias ConfigurableCell = UITableViewCell & Configurable !101
102. typealias BoardMenu = MenuView<BoardMenuOption> let menuView = BoardMenu(didSelectOption: { option in print(option) }) menuView.configure(options: [.rename, .delete]) typealias ConfigurableCell = UITableViewCell & Configurable // before !102 class MenuView<OptionCell>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionCell: ConfigurableCell { typealias OptionType = OptionCell.T // ... }
103. typealias BoardMenu = MenuView<BoardMenuOption> let menuView = BoardMenu(didSelectOption: { option in print(option) }) menuView.configure(options: [.rename, .delete]) typealias ConfigurableCell = UITableViewCell & Configurable // before !103 class MenuView<OptionCell>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionCell: ConfigurableCell { typealias OptionType = OptionCell.T // ... }
104. typealias BoardMenu = MenuView<MenuOptionCell> let menuView = BoardMenu(didSelectOption: { option in print(option) }) menuView.configure(options: [.rename, .delete]) typealias ConfigurableCell = UITableViewCell & Configurable // after And it just works! !104 class MenuView<OptionCell>: ConfigurableView, UITableViewDataSource, UITableViewDelegate where OptionCell: ConfigurableCell { typealias OptionType = OptionCell.T // ... }
105. Use Case: Status Menu !105
106. Use Case: Status Menu struct Status { let title: String let backgroundColor: UIColor } !106
107. Use Case: Status Menu struct Status { let title: String let backgroundColor: UIColor } class StatusCell: UITableViewCell, Configurable { let statusColorView = UIView() let lblTitle = UILabel() func setupViews() { ... } func configure(with status: Status) { lblTitle.text = status.title statusColorView.backgroundColor = status.backgroundColor } } !107
108. Use Case: Status Menu struct Status { let title: String let backgroundColor: UIColor } class StatusCell: UITableViewCell, Configurable { let statusColorView = UIView() let lblTitle = UILabel() func setupViews() { ... } func configure(with status: Status) { lblTitle.text = status.title statusColorView.backgroundColor = status.backgroundColor } } !108
109. Use Case: Status Menu struct Status { let title: String // “Done” let backgroundColor: UIColor // .doneGreen } class StatusCell: UITableViewCell, Configurable { let statusColorView = UIView() let lblTitle = UILabel() func setupViews() { ... } func configure(with status: Status) { lblTitle.text = status.title statusColorView.backgroundColor = status.backgroundColor } } !109
110. let statuses = [ Status(title: “Working on it", backgroundColor: .workingOrange), Status(title: "Done", backgroundColor: .doneGreen), Status(title: "Stuck", backgroundColor: .stuckRed) ] !110
111. let statuses = [ Status(title: “Working on it", backgroundColor: .workingOrange), Status(title: "Done", backgroundColor: .doneGreen), Status(title: "Stuck", backgroundColor: .stuckRed) ] typealias StatusMenu = MenuView<StatusCell> let menuView = StatusMenu(didSelectOption: { status in print(status.title) }) menuView.configure(options: statuses) !111
112. let statuses = [ Status(title: “Working on it", backgroundColor: .workingOrange), Status(title: "Done", backgroundColor: .doneGreen), Status(title: "Stuck", backgroundColor: .stuckRed) ] typealias StatusMenu = MenuView<StatusCell> let menuView = StatusMenu(didSelectOption: { status in print(status.title) }) menuView.configure(options: statuses) !112
113. • Super reusable views (shadow, appearance, …) • Super reusable behaviors (animations, transitions, …) • Consistent UI/UX • Scalable - change the whole look in one place What’s in it for me? And will make your design team love you even more !113
114. Where to go from here? • Xcode Playground • Swift Generics Manifesto • Gentle Generics by John Sundell • David Hart - Swift Generics - The 5 Stages of PATs !114
115. Questions! !115
116. Thank You !116