Swift 风格指南

private let maximumWidgetCount = 100

class WidgetContainer {
  var widgetButton: UIButton
  let widgetHeightPercentage = 0.85
}

let MAX_WIDGET_COUNT = 100

class app_widgetContainer {
  var wBut: UIButton
  let wHeightPct = 0.85
}

func dateFromString(dateString: String) -> NSDate
func convertPointAt(#column: Int,#row: Int) -> CGPoint
func timedAction(#delay: NSTimeInterval,perform action: SKAction) -> SKAction!

// 调用方式如下：
dateFromString("2014-03-14")
convertPointAt(column: 42,row: 13)
timedAction(delay: 1.0,perform: someOtherAction)

class Guideline {
  func combineWithString(incoming: String,options: Dictionary?) { ... }
  func upVoteBy(amount: Int) { ... }
}

enum Shape {
  case Rectangle
  case Square
  case Triangle
  case Circle
}

import SomeModule

let myClass = MyModule.UsefulClass()

if user.isHappy {
  // Do something
} else {
  // Do something else
}

if user.isHappy
{
    // Do something
}
else {
    // Do something else
}

class Circle: Shape {
  var x: Int,y: Int
  var radius: Double
  var diameter: Double {
    get {
      return radius * 2
    }
    set {
      radius = newValue / 2
    }
  }

  init(x: Int,y: Int,radius: Double) {
    self.x = x
    self.y = y
    self.radius = radius
  }

  convenience init(x: Int,diameter: Double) {
    self.init(x: x,y: y,radius: diameter / 2)
  }

  func describe() -> String {
    return "I am a circle at \(centerString()) with an area of \(computeArea())"
  }

  override func computeArea() -> Double {
    return M_PI * radius * radius
  }

  private func centerString() -> String {
    return "(\(x),\(y))"
  }
}

class BoardLocation {
  let row: Int,column: Int

  init(row: Int,column: Int) {
    self.row = row
    self.column = column

    let closure = {
      println(self.row)
    }
  }
}

class MyViewcontroller: UIViewController {
  // class stuff here
}

// MARK: - UITableViewDataSource
extension MyViewcontroller: UITableViewDataSource {
  // table view data source methods
}

// MARK: - uiscrollviewdelegate
extension MyViewcontroller: uiscrollviewdelegate {
  // scroll view delegate methods
}

class MyViewcontroller: UIViewController,UITableViewDataSource,uiscrollviewdelegate {
  // all methods
}

var diameter: Double {
  return radius * 2
}

var diameter: Double {
  get {
    return radius * 2
  }
}

func reticulateSplines(spline: [Double]) -> Bool {
  // reticulate code goes here
}

func reticulateSplines(spline: [Double],adjustmentFactor: Double,
 translateConstant: Int,comment: String) -> Bool {
  // reticulate code goes here
}

UIView.animateWithDuration(1.0) {
  self.myView.alpha = 0
}

UIView.animateWithDuration(1.0,
  animations: {
    self.myView.alpha = 0
  },
  completion: { finished in
    self.myView.removeFromSuperview()
  }
)

UIView.animateWithDuration(1.0,animations: {
  self.myView.alpha = 0
})

UIView.animateWithDuration(1.0,
  animations: {
    self.myView.alpha = 0
  }) { f in
    self.myView.removeFromSuperview()
}

attendeeList.sort { a,b in
  a > b
}

let width = 120.0                                    // Double
let widthString = (width as NSNumber).stringValue    // String

let width: NSNumber = 120.0                          // NSNumber
let widthString: Nsstring = width.stringValue        // Nsstring

self.textContainer?.textLabel?.setNeedsdisplay()

if let textContainer = self.textContainer {
  // do many things with textContainer
}

var subview: UIView?
var volume: Double?

// later on...
if let subview = subview,volume = volume {
  // do something with unwrapped subview and volume
}

var optionalSubview: UIView?
var volume: Double?

if let unwrappedSubview = optionalSubview {
  if let realVolume = volume {
    // do something with unwrappedSubview and realVolume
  }
}

let bounds = CGRect(x: 40,y: 20,width: 120,height: 80)
let centerPoint = CGPoint(x: 96,y: 42)

let bounds = CGRectMake(40,20,120,80)
let centerPoint = CGPointMake(96,42)

let message = "Click the button"
let currentBounds = computeViewBounds()
var names = [String]()
let maximumWidth: CGFloat = 106.5

let message: String = "Click the button"
let currentBounds: CGRect = computeViewBounds()
var names: [String] = []

var deviceModels: [String]
var employees: [Int: String]
var faxnumber: Int?

var deviceModels: Array<String>
var employees: Dictionary<Int,String>
var faxnumber: Optional<Int>

for _ in 0..<3 {
  println("Hello three times")
}

for (index,person) in enumerate(attendeeList) {
  println("\(person) is at position #\(index)")
}

for var i = 0; i < 3; i++ {
  println("Hello three times")
}

for var i = 0; i < attendeeList.count; i++ {
  let person = attendeeList[i]
  println("\(person) is at position #\(i)")
}