端端舝

Swift 2.0
劐載萸ㄗ分中凶中ㄘ引午戶

Representing and Throwing Errors
// Error毛隅膽允月
enum VendingMachineError: ErrorType {
case InvalidSelection
case InsufficientFunds(coinsNeeded: Int)
case OutOfStock
}
// Error毛throw允月
throw VendingMachineError.InsufficientFunds(coinsNeeded: 5)

Handling Errors
class VendingMachine {
// Error毛throw允月function卞反throws勾仃月
func vend(name: String, coins: Int) throws -> Int {
guard let item = inventory[name] else {
throw VendingMachineError.InvalidSelection
}
return coins - item.price
}
}

Handling Errors
// Error毛�I燴仄卅中及匹﹜throws毛勾仃化網太堤仄啋卞￤六月
func buyFavoriteSnack(person: String, coins: Int) throws -> Int {
let snackName = favoriteSnacks[person] ?? "Candy Bar"
// Error毛throw允月function及網太堤仄啋反﹜try仄卅中午申伙玉巨仿奈
return try vendingMachine.vend(snackName, coins: coins)
}

Handling Errors
// Error毛do 每 catch匹�I燴允月
func buyFavoriteSnack(person: String, coins: Int) -> Int {
do {
return try vendingMachine.vend(snackName, coins: coins)
} catch VendingMachineError.InvalidSelection {
print("Invalid selection.")
} catch VendingMachineError.InsufficientFunds(let coinsNeeded) {
print("Please insert an additional (coinsNeeded) coins.")
} catch {
print("Unknown Error.")
}
}

Handling Errors
// try?卞允月午﹜return互Optional卞卅月
// Error及午五反﹜仿件正奶丞巨仿奈卞卅日內﹜return互nil卞卅月
return try? vendingMachine.vend(snackName, coins: coins) ?? coins
}

Handling Errors
// try!卞允月午﹜申伙玉巨仿奈反剠仁卅月仃升﹜
// Error逃汜媆卞反仿件正奶丞巨仿奈卞卅月及匹峉�
return try! vendingMachine.vend(snackName, coins: coins)
}

Specifying Cleanup Actions
func processFile(filename: String) throws {
if exists(filename) {
let file = open(filename)
defer { // 嶱中凶伉末奈旦及寯元月�I燴毛輪仁卞𤩸中午仁
close(file)
}
while let line = try file.readline() {
// TODO
}
// scope皺賸媆卞defer及笢互網壬木化﹜伉末奈旦互寯元日木月
// 肮元scope卞恚杅及defer毛𤩸中凶午五反﹜欄�卞網壬木月
}
}

Repeat-While
// do 每 while午肮元
// 珨隙灍俴仄化井日靜曰殿仄沭璃毛瓚剿允月
var num: Int
repeat {
num = random()
} while num < 100

Guard
func vend(name: String, coins: Int) throws -> Int {
// ゴ枑沭璃𨈘偩卞杻趙仄凶沭璃煦嶊
// else引匹本永玄卅及匹﹜淏仄中源及沭璃毛𤩸仁
// let / var匹哫晟仄凶劐杅反guard及俋及scope卞卅月
// else反return, break, continue, throw匹㠙仃卅中午戊件由奶伙巨仿奈
guard let item = inventory[name] else {
throw VendingMachineError.InvalidSelection
}
return coins - item.price
}

If Case(Pattern Match)
enum Gender {
case Male, Female
}
let person: (String, Int, Gender) = ("Ken", 33, .Male)
// if午guard匹手case互妏尹月
if case (_, 20..<65, _) = person {
print("Worker!")
}
if case (let name, _, .Male) = person {
print(name)
}

Optional Pattern
let nums: [Int?] = [nil, 2, 3, nil, 5]
for case let num? in nums { // nil毛壺中凶伙奈皿﹝num反Int?元扎卅仁化Int
print(num) // 2, 3, 5
}
for case let num? in nums where num % 2 == 1 {
print(num) // 3, 5
}

Checking API Availability
// 仿件正奶丞及皿仿永玄石奈丞午田奈斥亦件ㄗ眕奻ㄘ毛瓚隅匹五月
// if午guard及沭璃匹及心妏尹月
// 皿仿永玄石奈丞反﹜☆iOS★☆OSX★☆watchOS★互妏尹月
// 田奈斥亦件反﹜丟斥乓奈分仃井日扔皮穴奶瓜奈引匹𤩸仃月
// 郔摽及猁匼反﹜羯�☆*★卞卅月
if #available(iOS 9, OSX 10.10, *) {
// Use iOS 9 APIs on iOS, and use OS X v10.10 APIs on OS X
} else {
// Fall back to earlier iOS and OS X APIs
}

Protocol Extensions
protocol MyProtocol {
func abstractFunc()
func defaultFunc()
}
extension MyProtocol {
// function及犯白巧伙玄灍蚾毛𤩸仃月
func defaultFunc() { ＃ }
// protocol卞卅中function手𤩸仃月ㄗprivate手OKㄘ
func newFunc() { ＃ }
}

Protocol Extensions
// extension匹灍蚾仄凶丟末永玉反灍蚾仄卅仁化手OK
class MyClass: MyProtocol {
func abstractFunc() { ＃ }
}
MyClass().abstractFunc()
MyClass().defaultFunc()
MyClass().newFunc()
class MyClass2: MyProtocol {
func abstractFunc() { ＃ }
func defaultFunc() { ＃ } // extension及犯白巧伙玄灍蚾反奻𤩸五匹五月
func newFunc() { ＃ } // extension分仃卞𤩸中凶丟末永玉手奻𤩸五匹五月
}

Enumerations
Implicitly Assigned Raw Values
// 郔場及猁匼毛隴尨仄卅中�磁反0卞卅月
// 眕蔥及猁匼毛隴尨仄卅中�磁﹜眻ゴ及猁匼毛奶件弁伉丟件玄仄凶�卞卅月
enum Planet: Int {
// 0, 1, 5, 6, 7, 10, 11, 12
case Mercury, Venus, Earth = 5, Mars, Jupiter, Saturn = 10, Uranus, Neptune
}
// 隴尨仄卅中�磁反﹜靡ゴ午肮元卞卅月
enum CompassPoint: String {
// "North", "鰍", "East", "West"
case North, South = "鰍", East, West
}

Enumerations
Recursive Enumerations
// 赻旯毛生旦玄仄凶enum互釬木月
// 生旦玄允月手及卞indirect毛勾仃月
enum ArithmeticExpression {
case Number(Int)
indirect case Addition(ArithmeticExpression, ArithmeticExpression)
indirect case Multiplication(ArithmeticExpression, ArithmeticExpression)
}
// enum赻极卞勾仃月仇午手匹五月
indirect enum ArithmeticExpression {
case Number(Int)
case Addition(ArithmeticExpression, ArithmeticExpression)
case Multiplication(ArithmeticExpression, ArithmeticExpression)
}

Expressions
Initializer Expression
class MyClass {
init(i: Int) { ＃ }
init(s: String) { ＃ }
init(i: Int, s: String) { ＃ }
}
// Initializer毛龰木月方丹卞卅勻凶
let init1: Int -> MyClass = MyClass.init
let init2: String -> MyClass = MyClass.init
let init3: (Int, String) -> MyClass = MyClass.init
let initializer: Int -> String = String.init
let s: String = [1, 2, 3].map(initializer).reduce("", combine: +) // "123"

Functions
Variadic Parameters
// 褫劐墿竘杅毛藺帣眕俋卞手𤩸仃月ㄗ凶分仄1勾引匹ㄘ
func print(items: Any..., separator: String = default, terminator: String = default)
print(1, 2, 3, separator: ", ", terminator: ".") // "1, 2, 3."

String Literals
// 恅趼蹈伉氾仿伙及+栳呾赽匹及磐磁反﹜
// 灍俴媆匹反卅仁﹜戊件由奶伙媆卞�I燴今木月
// textA午textB反灍俴媆卞反肮元
let textA = "Hello " + "world"
let textB = "Hello world"

? Function及仿矛伙及勾仃源互劐載卞卅勻化月
每菴珨竘杅卞#勾仃日木卅仁卅勻凶﹝仃升﹜赻蚕卞仿
矛伙毛勾仃日木月
每菴珨竘杅眕俋卞#毛勾仃月午﹜網少媆卞仿矛伙祥
猁
? Label葆五及break匹﹜if午switch手break匹五月
方丹卞卅勻凶

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