From 328a4f1babe167e94858b92faaa9caa19aa8aade Mon Sep 17 00:00:00 2001 From: "C. Bess" Date: Sat, 23 Aug 2014 22:48:10 -0500 Subject: - add more examples; update examples - now runs in the Xcode 6 b6 playground - add MARK sections --- swift.html.markdown | 206 ++++++++++++++++++++++++++++++++++------------------ 1 file changed, 135 insertions(+), 71 deletions(-) (limited to 'swift.html.markdown') diff --git a/swift.html.markdown b/swift.html.markdown index a47b085a..5ba160b8 100644 --- a/swift.html.markdown +++ b/swift.html.markdown @@ -2,6 +2,7 @@ language: swift contributors: - ["Grant Timmerman", "http://github.com/grant"] + - ["Christopher Bess", "http://github.com/cbess"] filename: learnswift.swift --- @@ -11,21 +12,34 @@ See also Apple's [getting started guide](https://developer.apple.com/library/pre ```js // -// Basics +// MARK: Basics // println("Hello, world") + var myVariable = 42 +//let fƒ∆ = "value" // unicode in variable names let myConstant = 3.1415926 +let convenience = "keyword" // contextual variable name +let weak = "keyword"; let override = "another keyword" // statements can be separated by a semi-colon +let `class` = "keyword" // backticks allow keywords to be used as variable names let explicitDouble: Double = 70 +let intValue = 0007 // 7 +let largeIntValue = 77_000 // 77000 let label = "some text " + String(myVariable) // Casting let piText = "Pi = \(myConstant)" // String interpolation var optionalString: String? = "optional" // Can be nil optionalString = nil +/* +Comment here + /* + Nested comment here + */ +*/ // -// Arrays and Dictionaries +// MARK: Collections // // Array @@ -35,65 +49,66 @@ let emptyArray = [String]() // Dictionary var occupations = [ - "Malcolm": "Captain", - "kaylee": "Mechanic" + "Malcolm": "Captain", + "kaylee": "Mechanic" ] occupations["Jayne"] = "Public Relations" let emptyDictionary = Dictionary() // -// Control Flow +// MARK: Control Flow // // for loop (array) let myArray = [1, 1, 2, 3, 5] for value in myArray { - if value == 1 { - println("One!") - } else { - println("Not one!") - } + if value == 1 { + println("One!") + } else { + println("Not one!") + } } // for loop (dictionary) +var dict = ["one": 1, "two": 2] for (key, value) in dict { - println("\(key): \(value)") + println("\(key): \(value)") } // for loop (range) for i in -1...1 { // [-1, 0, 1] - println(i) + println(i) } // use ..< to exclude the last number // while loop var i = 1 while i < 1000 { - i *= 2 + i *= 2 } // do-while loop do { - println("hello") + println("hello") } while 1 == 2 // Switch let vegetable = "red pepper" switch vegetable { case "celery": - let vegetableComment = "Add some raisins and make ants on a log." + let vegetableComment = "Add some raisins and make ants on a log." case "cucumber", "watercress": - let vegetableComment = "That would make a good tea sandwich." + let vegetableComment = "That would make a good tea sandwich." case let x where x.hasSuffix("pepper"): - let vegetableComment = "Is it a spicy \(x)?" + let vegetableComment = "Is it a spicy \(x)?" default: // required (in order to cover all possible input) - let vegetableComment = "Everything tastes good in soup." + let vegetableComment = "Everything tastes good in soup." } // -// Functions +// MARK: Functions // // Functions are a first-class type, meaning they can be nested @@ -101,31 +116,31 @@ default: // required (in order to cover all possible input) // Function func greet(name: String, day: String) -> String { - return "Hello \(name), today is \(day)." + return "Hello \(name), today is \(day)." } greet("Bob", "Tuesday") // Function that returns multiple items in a tuple func getGasPrices() -> (Double, Double, Double) { - return (3.59, 3.69, 3.79) + return (3.59, 3.69, 3.79) } -// Args +// Variadic Args func setup(numbers: Int...) {} // Passing and returning functions func makeIncrementer() -> (Int -> Int) { - func addOne(number: Int) -> Int { - return 1 + number - } - return addOne + func addOne(number: Int) -> Int { + return 1 + number + } + return addOne } var increment = makeIncrementer() increment(7) // -// Closures +// MARK: Closures // var numbers = [1, 2, 6] @@ -135,93 +150,142 @@ var numbers = [1, 2, 6] // `->` separates the arguments and return type // `in` separates the closure header from the closure body numbers.map({ - (number: Int) -> Int in - let result = 3 * number - return result - }) + (number: Int) -> Int in + let result = 3 * number + return result +}) // When the type is known, like above, we can do this numbers = numbers.map({ number in 3 * number }) -//Or even this +// Or even this //numbers = numbers.map({ $0 * 3 }) print(numbers) // [3, 6, 18] +// Trailing closure +numbers = sorted(numbers) { $0 > $1 } + +print(numbers) // [18, 6, 3] + +// Super shorthand, since the < operator infers the types + +numbers = sorted(numbers, < ) + +print(numbers) // [3, 6, 18] // -// Classes +// MARK: Classes // +class Shape { + func getArea() -> Int { + return 0; + } +} + // All methods and properties of a class are public. // If you just need to store data in a // structured object, you should use a `struct` // A simple class `Square` extends `Shape` class Rect: Shape { - var sideLength: Int = 1 - - // Custom getter and setter property - var perimeter: Int { - get { - return 4 * sideLength + var sideLength: Int = 1 + + // Custom getter and setter property + var perimeter: Int { + get { + return 4 * sideLength + } + set { + sideLength = newValue / 4 + } } - set { - sideLength = newValue / 4 + + // If you don't need a custom getter and setter, + // but still want to run code before and after getting or setting + // a property, you can use `willSet` and `didSet` + var identifier: String = "defaultID" { + willSet(someIdentifier) { + print(someIdentifier) + } } - } - - init(sideLength: Int) { - super.init() - self.sideLength = sideLength - } - - func shrink() { - if sideLength > 0 { - --sideLength + + init(sideLength: Int) { + super.init() + self.sideLength = sideLength + } + + func shrink() { + if sideLength > 0 { + --sideLength + } } - } + + override func getArea() -> Int { + return sideLength * sideLength + } +} - override func getArea() -> Int { - return sideLength * sideLength - } +class Square: Rect { + convenience init() { + self.init(sideLength: 5) + } } -var mySquare = new Square(sideLength: 5) + +var mySquare = Square() print(mySquare.getArea()) // 25 mySquare.shrink() print(mySquare.sideLength) // 4 -// If you don't need a custom getter and setter, -// but still want to run code before and after getting or setting -// a property, you can use `willSet` and `didSet` - // -// Enums +// MARK: Enums // // Enums can optionally be of a specific type or on their own. // They can contain methods like classes. enum Suit { - case Spades, Hearts, Diamonds, Clubs - func getIcon() -> String { - switch self { - case .Spades: return "♤" - case .Hearts: return "♡" - case .Diamonds: return "♢" - case .Clubs: return "♧" + case Spades, Hearts, Diamonds, Clubs + func getIcon() -> String { + switch self { + case .Spades: return "♤" + case .Hearts: return "♡" + case .Diamonds: return "♢" + case .Clubs: return "♧" + } } - } } // -// Other +// MARK: Other // // `protocol`: Similar to Java interfaces. -// `extension`s: Add extra functionality to an already created type +protocol ShapeGenerator { + func buildShape() -> Shape +} + +// `extension`s: Add extra functionality to an already existing type +extension Square: Printable { + var description: String { + return "Area: \(self.getArea()) - ID: \(self.identifier)" + } +} + +println("Square: \(mySquare)") + // Generics: Similar to Java. Use the `where` keyword to specify the // requirements of the generics. +func findIndex(array: [T], valueToFind: T) -> Int? { + for (index, value) in enumerate(array) { + if value == valueToFind { + return index + } + } + return nil +} + ``` -- cgit v1.2.3