From cf3676cd84f044b7782619b12d5e2da956ceed88 Mon Sep 17 00:00:00 2001 From: futantan Date: Mon, 29 Jun 2015 19:02:28 +0800 Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0=E7=A4=BA=E4=BE=8B=E4=BB=A3?= =?UTF-8?q?=E7=A0=81=20println()=20->=20print()?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- source/chapter2/22_Protocols.md | 52 ++++++++++++++++----------------- 1 file changed, 26 insertions(+), 26 deletions(-) diff --git a/source/chapter2/22_Protocols.md b/source/chapter2/22_Protocols.md index d17abb5d..dad93021 100644 --- a/source/chapter2/22_Protocols.md +++ b/source/chapter2/22_Protocols.md @@ -1,4 +1,4 @@ -> 翻译：[geek5nan](https://github.com/geek5nan) +> 翻译：[geek5nan](https://github.com/geek5nan) > 校对：[dabing1022](https://github.com/dabing1022) # 协议 @@ -164,9 +164,9 @@ class LinearCongruentialGenerator: RandomNumberGenerator { } } let generator = LinearCongruentialGenerator() -println("Here's a random number: \(generator.random())") +print("Here's a random number: \(generator.random())") // 输出 : "Here's a random number: 0.37464991998171" -println("And another one: \(generator.random())") +print("And another one: \(generator.random())") // 输出 : "And another one: 0.729023776863283" ``` @@ -178,7 +178,7 @@ println("And another one: \(generator.random())") 如果协议中的实例方法打算改变其`遵循者`实例的类型，那么在协议定义时需要在方法前加`mutating`关键字，才能使`结构体，枚举`来采用并满足协议中对方法的规定。 ->注意: +>注意: >用`类`实现协议中的`mutating`方法时，不用写`mutating`关键字;用`结构体`，`枚举`实现协议中的`mutating`方法时，必须写`mutating`关键字。 如下所示，`Togglable`协议含有名为`toggle`的突变实例方法。根据名称推测，`toggle`方法应该是用于切换或恢复其`遵循者`实例或其属性的类型。 @@ -255,7 +255,7 @@ class SomeSuperClass { } } - + class SomeSubClass: SomeSuperClass, SomeProtocol { // "required" from SomeProtocol conformance; "override" from SomeSuperClass required override init() { @@ -277,7 +277,7 @@ class SomeSubClass: SomeSuperClass, SomeProtocol { 尽管`协议`本身并不实现任何功能，但是`协议`可以被当做类型来使用。 -使用场景: +使用场景: * `协议类型`作为函数、方法或构造器中的参数类型或返回值类型 * `协议类型`作为常量、变量或属性的类型 @@ -314,7 +314,7 @@ class Dice { ```swift var d6 = Dice(sides: 6,generator: LinearCongruentialGenerator()) for _ in 1...5 { - println("Random dice roll is \(d6.roll())") + print("Random dice roll is \(d6.roll())") } //输出结果 //Random dice roll is 3 @@ -333,7 +333,7 @@ for _ in 1...5 { 委托模式可以用来响应特定的动作或接收外部数据源提供的数据，而无需要知道外部数据源的所属类型(*译者注:只要求外部数据源`遵循`某协议*)。 -下文是两个基于骰子游戏的协议: +下文是两个基于骰子游戏的协议: ```swift protocol DiceGame { @@ -349,7 +349,7 @@ protocol DiceGameDelegate { ``` `DiceGame`协议可以在任意含有骰子的游戏中实现，`DiceGameDelegate`协议可以用来追踪`DiceGame`的游戏过程 - + 如下所示，`SnakesAndLadders`是`Snakes and Ladders`(译者注:[Control Flow](2)章节有该游戏的详细介绍)游戏的新版本。新版本使用`Dice`作为骰子，并且实现了`DiceGame`和`DiceGameDelegate`协议，后者用来记录游戏的过程: ```swift @@ -403,16 +403,16 @@ class DiceGameTracker: DiceGameDelegate { func gameDidStart(game: DiceGame) { numberOfTurns = 0 if game is SnakesAndLadders { - println("Started a new game of Snakes and Ladders") + print("Started a new game of Snakes and Ladders") } - println("The game is using a \(game.dice.sides)-sided dice") + print("The game is using a \(game.dice.sides)-sided dice") } func game(game: DiceGame, didStartNewTurnWithDiceRoll diceRoll: Int) { ++numberOfTurns - println("Rolled a \(diceRoll)") + print("Rolled a \(diceRoll)") } func gameDidEnd(game: DiceGame) { - println("The game lasted for \(numberOfTurns) turns") + print("The game lasted for \(numberOfTurns) turns") } } ``` @@ -468,7 +468,7 @@ extension Dice: TextRepresentable { ```swift let d12 = Dice(sides: 12,generator: LinearCongruentialGenerator()) -println(d12.asText()) +print(d12.asText()) // 输出 "A 12-sided dice" ``` @@ -480,7 +480,7 @@ extension SnakesAndLadders: TextRepresentable { return "A game of Snakes and Ladders with \(finalSquare) squares" } } -println(game.asText()) +print(game.asText()) // 输出 "A game of Snakes and Ladders with 25 squares" ``` @@ -504,7 +504,7 @@ extension Hamster: TextRepresentable {} ```swift let simonTheHamster = Hamster(name: "Simon") let somethingTextRepresentable: TextRepresentable = simonTheHamster -println(somethingTextRepresentable.asText()) +print(somethingTextRepresentable.asText()) // 输出 "A hamster named Simon" ``` @@ -523,7 +523,7 @@ let things: [TextRepresentable] = [game,d12,simonTheHamster] ```swift for thing in things { - println(thing.asText()) + print(thing.asText()) } // A game of Snakes and Ladders with 25 squares // A 12-sided dice @@ -583,7 +583,7 @@ extension SnakesAndLadders: PrettyTextRepresentable { 任意`SankesAndLadders`的实例都可以使用`asPrettyText()`方法。 ```swift -println(game.asPrettyText()) +print(game.asPrettyText()) // A game of Snakes and Ladders with 25 squares: // ○ ○ ▲ ○ ○ ▲ ○ ○ ▲ ▲ ○ ○ ○ ▼ ○ ○ ○ ○ ▼ ○ ○ ▼ ○ ▼ ○ ``` @@ -624,7 +624,7 @@ struct Person: Named, Aged { var age: Int } func wishHappyBirthday(celebrator: protocol) { - println("Happy birthday \(celebrator.name) - you're \(celebrator.age)!") + print("Happy birthday \(celebrator.name) - you're \(celebrator.age)!") } let birthdayPerson = Person(name: "Malcolm", age: 21) wishHappyBirthday(birthdayPerson) @@ -642,9 +642,9 @@ wishHappyBirthday(birthdayPerson) 使用`is`和`as`操作符来检查协议的一致性或转化协议类型。检查和转化的语法和之前相同(*详情查看[Typy Casting章节](5)*): -* `is`操作符用来检查实例是否`遵循`了某个`协议`。 +* `is`操作符用来检查实例是否`遵循`了某个`协议`。 * `as?`返回一个可选值，当实例`遵循`协议时，返回该协议类型;否则返回`nil` -* `as`用以强制向下转型。 +* `as`用以强制向下转型。 ```swift @objc protocol HasArea { @@ -697,9 +697,9 @@ let objects: [AnyObject] = [ ```swift for object in objects { if let objectWithArea = object as? HasArea { - println("Area is \(objectWithArea.area)") + print("Area is \(objectWithArea.area)") } else { - println("Something that doesn't have an area") + print("Something that doesn't have an area") } } // Area is 12.5663708 @@ -754,7 +754,7 @@ for object in objects { `count`属性用于存储当前的值，`increment`方法用来为`count`赋值。 `increment`方法通过`可选链`，尝试从两种`可选成员`中获取`count`。 - + 1. 由于`dataSource`可能为`nil`，因此在`dataSource`后边加上了`?`标记来表明只在`dataSource`非空时才去调用`incrementForCount`方法。 2. 即使`dataSource`存在，但是也无法保证其是否实现了`incrementForCount`方法，因此在`incrementForCount`方法后边也加有`?`标记 @@ -776,7 +776,7 @@ var counter = Counter() counter.dataSource = ThreeSource() for _ in 1...4 { counter.increment() - println(counter.count) + print(counter.count) } // 3 // 6 @@ -807,7 +807,7 @@ counter.count = -4 counter.dataSource = TowardsZeroSource() for _ in 1...5 { counter.increment() - println(counter.count) + print(counter.count) } // -3 // -2