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| author | Geoff Liu <g@geoffliu.me> | 2015-01-18 13:07:39 -0700 | 
|---|---|---|
| committer | Geoff Liu <g@geoffliu.me> | 2015-01-18 13:07:39 -0700 | 
| commit | 31faf1a6a1c35802cf3676ec1a7f54d86411b566 (patch) | |
| tree | 5ccca54b8837fec9a8d6d60d2bda6db4162078e7 /swift.html.markdown | |
| parent | 40c38c125b94430b518d7e402d595694149b7c53 (diff) | |
| parent | c053f1559bb357d9e8ced2452096bf3a95cc7ddb (diff) | |
Merge branch 'master' of github.com:geoffliu/learnxinyminutes-docs
Diffstat (limited to 'swift.html.markdown')
| -rw-r--r-- | swift.html.markdown | 69 | 
1 files changed, 47 insertions, 22 deletions
diff --git a/swift.html.markdown b/swift.html.markdown index 005e511c..0d1d2df4 100644 --- a/swift.html.markdown +++ b/swift.html.markdown @@ -6,7 +6,7 @@ contributors:  filename: learnswift.swift  --- -Swift is a programming language for iOS and OS X development created by Apple. Designed to coexist with Objective-C and to be more resilient against erroneous code, Swift was introduced in 2014 at Apple's developer conference WWDC. It is built with the LLVM compiler included in Xcode 6 beta. +Swift is a programming language for iOS and OS X development created by Apple. Designed to coexist with Objective-C and to be more resilient against erroneous code, Swift was introduced in 2014 at Apple's developer conference WWDC. It is built with the LLVM compiler included in Xcode 6+.  The official [Swift Programming Language](https://itunes.apple.com/us/book/swift-programming-language/id881256329) book from Apple is now available via iBooks. @@ -23,7 +23,7 @@ import UIKit  // Xcode supports landmarks to annotate your code and lists them in the jump bar  // MARK: Section mark  // TODO: Do something soon -// FIXME Fix this code +// FIXME: Fix this code  println("Hello, world") @@ -55,8 +55,8 @@ println("Build value: \(buildValue)") // Build value: 7  /*      Optionals are a Swift language feature that allows you to store a `Some` or      `None` value. -     -    Because Swift requires every property to have a value, even nil must be  + +    Because Swift requires every property to have a value, even nil must be      explicitly stored as an Optional value.      Optional<T> is an enum. @@ -94,7 +94,8 @@ var anyObjectVar: AnyObject = 7  anyObjectVar = "Changed value to a string, not good practice, but possible."  /* -Comment here +    Comment here +          /*          Nested comments are also supported      */ @@ -112,8 +113,9 @@ Comment here  // Array  var shoppingList = ["catfish", "water", "lemons"]  shoppingList[1] = "bottle of water" -let emptyArray = [String]() // immutable -var emptyMutableArray = [String]() // mutable +let emptyArray = [String]() // let == immutable +let emptyArray2 = Array<String>() // same as above +var emptyMutableArray = [String]() // var == mutable  // Dictionary @@ -122,8 +124,9 @@ var occupations = [      "kaylee": "Mechanic"  ]  occupations["Jayne"] = "Public Relations" -let emptyDictionary = [String: Float]() // immutable -var emptyMutableDictionary = [String: Float]() // mutable +let emptyDictionary = [String: Float]() // let == immutable +let emptyDictionary2 = Dictionary<String, Float>() // same as above +var emptyMutableDictionary = [String: Float]() // var == mutable  // @@ -165,14 +168,16 @@ do {  } while 1 == 2  // Switch +// Very powerful, think `if` statements with syntax candy +// They support String, object instances, and primitives (Int, Double, etc)  let vegetable = "red pepper"  switch vegetable {  case "celery":      let vegetableComment = "Add some raisins and make ants on a log."  case "cucumber", "watercress":      let vegetableComment = "That would make a good tea sandwich." -case let x where x.hasSuffix("pepper"): -    let vegetableComment = "Is it a spicy \(x)?" +case let localScopeValue where localScopeValue.hasSuffix("pepper"): +    let vegetableComment = "Is it a spicy \(localScopeValue)?"  default: // required (in order to cover all possible input)      let vegetableComment = "Everything tastes good in soup."  } @@ -186,21 +191,28 @@ default: // required (in order to cover all possible input)  // in functions and can be passed around  // Function with Swift header docs (format as reStructedText) +  /** -A greet operation +    A greet operation -- A bullet in docs -- Another bullet in the docs +    - A bullet in docs +    - Another bullet in the docs -:param: name A name -:param: day A day -:returns: A string containing the name and day value. +    :param: name A name +    :param: day A day +    :returns: A string containing the name and day value.  */  func greet(name: String, day: String) -> String {      return "Hello \(name), today is \(day)."  }  greet("Bob", "Tuesday") +// similar to above except for the function parameter behaviors +func greet2(#requiredName: String, externalParamName localParamName: String) -> String { +    return "Hello \(requiredName), the day is \(localParamName)" +} +greet2(requiredName:"John", externalParamName: "Sunday") +  // Function that returns multiple items in a tuple  func getGasPrices() -> (Double, Double, Double) {      return (3.59, 3.69, 3.79) @@ -281,7 +293,7 @@ print(numbers) // [3, 6, 18]  // Structures and classes have very similar capabilites  struct NamesTable { -    let names: [String] +    let names = [String]()      // Custom subscript      subscript(index: Int) -> String { @@ -291,8 +303,8 @@ struct NamesTable {  // Structures have an auto-generated (implicit) designated initializer  let namesTable = NamesTable(names: ["Me", "Them"]) -//let name = namesTable[2] -//println("Name is \(name)") // Name is Them +let name = namesTable[1] +println("Name is \(name)") // Name is Them  //  // MARK: Classes @@ -341,7 +353,7 @@ internal class Rect: Shape {      init(sideLength: Int) {          self.sideLength = sideLength -         // always super.init last when init custom properties +        // always super.init last when init custom properties          super.init()      } @@ -368,6 +380,9 @@ print(mySquare.getArea()) // 25  mySquare.shrink()  print(mySquare.sideLength) // 4 +// cast instance +let aShape = mySquare as Shape +  // compare instances, not the same as == which compares objects (equal to)  if mySquare === mySquare {      println("Yep, it's mySquare") @@ -393,6 +408,17 @@ enum Suit {      }  } +// Enum values allow short hand syntax, no need to type the enum type +// when the variable is explicitly declared +var suitValue: Suit = .Hearts + +// Non-Integer enums require direct raw value assignments +enum BookName: String { +    case John = "John" +    case Luke = "Luke" +} +println("Name: \(BookName.John.rawValue)") +  //  // MARK: Protocols @@ -490,5 +516,4 @@ println(mySquare.sideLength) // 4  // change side length using custom !!! operator, increases size by 3  !!!mySquare  println(mySquare.sideLength) // 12 -  ```  | 
