import UIKit
// repeat...while循环，相当于do...while
var m = 100
repeat {
m = m * 2
} while m < 100
print(m)
// for...in循环
var total = 0
for i in 0 ..< 4 {
total += i
}
print(total)
// 多个返回值的方法
func calculate(scores: [Int]) -> (min: Int, max : Int, sum: Int) {
var min = scores[0]
var max = scores[0]
var sum = 0
for score in scores {
if score > max {
max = score
} else if score < min {
min = score
}
sum += score
}
return (min, max, sum)
}
let statistics = calculate(scores: [5,3,25,33,2])
print(statistics.sum)
print(statistics.0)
// 传多个同类型的参数
func sumOf(numbers: Int...) -> Int {
var sum = 0
for number in numbers {
sum += number
}
return sum
}
sumOf(numbers: 4,3,2,45,33)
// 方法中定义方法
func returnFifteen() -> Int {
var y = 10
func add() {
y += 5
}
add()
return y
}
returnFifteen()
// 返回值是一个方法
func makeIncrement() -> ((Int) -> Int) {
func addOne(number: Int) -> Int {
return number + 1
}
return addOne
}
var increment = makeIncrement()
increment(7)
// 参数要传一个方法的方法
func hasAnyMatches(list: [Int], condition: (Int) -> Bool) -> Bool {
for item in list {
if condition(item) {
return true
}
}
return false
}
func lessThanTen(number: Int) -> Bool {
return number < 10
}
var numbers = [20, 9, 7, 12]
hasAnyMatches(list: numbers, condition: lessThanTen)
// 数组的map
numbers.map { (number: Int) -> Int in
let result = 3 * number
return result
}
let mappedNumers = numbers.map({ number in 3 * number})
print(mappedNumers)
let sortedNumbers = numbers.sort {$0 > $1}
print(sortedNumbers)
// 类
class NumberParser {
func singleNumberToChinese(number: Character) -> String {
switch number {
case "0":
return "零"
case "1":
return "一"
case "2":
return "二"
case "3":
return "三"
case "4":
return "四"
case "5":
return "五"
case "6":
return "六"
case "7":
return "七"
case "8":
return "八"
case "9":
return "九"
default:
return ""
}
}
}
// 类的实例化
let convertor = NumberParser()
let zeroString = convertor.singleNumberToChinese(number: "0")
print(zeroString)
// 变量
var string = "swift"
string = "Taylor"
// 类的继承
class NumbersParser: NumberParser {
// 单例
static let sharedInstance = NumbersParser()
func numberToChinese(number: Int) -> String {
let numbers = String(number).characters
var finalString = ""
for singleNumber in numbers {
let string = singleNumberToChinese(number: singleNumber)
finalString = "\(finalString)\(string)"
}
return finalString
}
}
let conventor = NumbersParser()
let yearString = conventor.numberToChinese(number: 2016)
print(yearString)
// 单例用法
let numberString = NumbersParser.sharedInstance.numberToChinese(number: 1234)
print(numberString)
// 类的重载
class YearParser: NumbersParser {
static let sharedYearParserInstance = YearParser()
override func numberToChinese(number: Int) -> String {
let numbersString = super.numberToChinese(number: number)
return "\(numbersString) 年"
}
}
let yearStr = YearParser.sharedYearParserInstance.numberToChinese(number: 2016)
print(yearStr)
// protocol
protocol SleepDelegate {
func canISleep() -> Bool
}
class Cat {
// ？表示delegate并不一定存在
var delegate: SleepDelegate?
func wantToSleep() {
// 首先对其进行拆包，只有delegate这个属性真的存在的时候，才能通过拆包
if let delegate = delegate {
if delegate.canISleep() {
print("Go To Sleep")
} else {
print("NO")
}
}
}
}
class Human: SleepDelegate {
func canISleep() -> Bool {
return false
}
}
let myCat = Cat()
myCat.delegate = Human()
myCat.wantToSleep()
// enum枚举
enum China: Int {
case Beijing = 0
case Shanghai
var description: String {
switch self {
case .Beijing:
return "北京"
case .Shanghai:
return "上海"
}
}
}
class City {
var name = China.Beijing
}
let beijing = City()
print(beijing.name.description)
// 直接输出enum的值
print(China.Shanghai.description)
// 类
class Shape {
var numberOfSides = 0
var name: String
init(name: String) {
self.name = name
}
func simpleDescription() -> String {
return "A shape with \(numberOfSides) sides."
}
}
var shape = Shape(name: "square")
shape.numberOfSides = 7
var shapeDescription = shape.simpleDescription()
print(shapeDescription)
print(shape.name)
class Square: Shape {
var sideLength: Double
init(sideLength: Double, name: String) {
self.sideLength = sideLength
super.init(name: name)
numberOfSides = 4
}
func area() -> Double {
return sideLength * sideLength
}
override func simpleDescription() -> String {
return "A square with sides of length \(sideLength)"
}
}
let test = Square(sideLength: 5.3, name: "square")
test.area()
test.simpleDescription()
class EquilateralTriangle: Shape {
var sideLength: Double = 0.0
init(sideLength: Double, name: String) {
self.sideLength = sideLength
super.init(name: name)
numberOfSides = 3
}
var perimeter: Double {
get {
return 3.0 * sideLength
}
set {
sideLength = newValue / 3.0
}
}
override func simpleDescription() -> String {
return "An equilateral triangle with sides of length \(sideLength)"
}
}
var triangle = EquilateralTriangle(sideLength: 3.1, name: "a triangle")
print(triangle.perimeter)
triangle.perimeter = 9.9
print(triangle.sideLength)
class TriangleAndSquare {
var triangle: EquilateralTriangle {
willSet {
square.sideLength = newValue.sideLength
}
}
var square: Square {
willSet {
triangle.sideLength = newValue.sideLength
}
}
init(size: Double, name: String) {
square = Square(sideLength: size, name: name)
triangle = EquilateralTriangle(sideLength: size, name: name)
}
}
var triangleAndSquare = TriangleAndSquare(size: 10, name: "another test shape")
print(triangleAndSquare.square.sideLength)
print(triangleAndSquare.triangle.sideLength)
triangleAndSquare.square = Square(sideLength: 50, name: "larger square")
print(triangleAndSquare.triangle.sideLength)
let optionalSquare: Square? = Square(sideLength: 2.5, name: "Optional Square")
let sideLength = optionalSquare?.sideLength
// 枚举
enum Rank: Int {
case ace = 1
case two, three, four, five, sex, seven, eight, nine, ten
case jack, queen, king
func simpleDescription() -> String {
switch self {
case .ace:
return "ace"
case .jack:
return "jack"
case .queen:
return "queen"
case .king:
return "king"
default:
return String(self.rawValue)
}
}
}
let ace = Rank.ace
let aceRawValue = ace.rawValue
if let convertedRank = Rank(rawValue: 3) {
let threeDescription = convertedRank.simpleDescription()
}
enum Suit {
case spades, hearts, diamonds, clubs
func simpleDescription() -> String {
switch self {
case .spades:
return "spades"
case .hearts:
return "hearts"
case .diamonds:
return "diamonds"
case .clubs:
return "clubs"
}
}
}
let hearts = Suit.hearts
let heartsDescription = hearts.simpleDescription()
enum ServerResponse {
case result(String, String)
case failure(String)
}
let success = ServerResponse.result("6:00 am", "8:09 pm")
let failure = ServerResponse.failure("out of cheese")
switch failure {
case let .result(sunrise, sunset):
print("Sunrise is at \(sunrise) and sunset is at \(sunset)")
case let .failure(message):
print("Failure... \(message)")
}
// 结构体
struct Card {
var rank: Rank
var suit: Suit
func simpleDescription() -> String {
return "The \(rank.simpleDescription()) of \(suit.simpleDescription())"
}
}
let threeOfSpades = Card(rank: .three, suit: .spades)
let threeOfSpadesDescription = threeOfSpades.simpleDescription()
// 协议protocol
protocol ExampleProtocol {
var simpleDescription: String {get}
mutating func adjust()
}
class SimpleClass: ExampleProtocol {
var simpleDescription: String = "A very simple class"
var anthorProperty: Int = 69105
func adjust() {
simpleDescription += " Now 100% adjusted."
}
}
var a = SimpleClass()
a.adjust()
let aDescription = a.simpleDescription
struct SimpleStructure: ExampleProtocol {
var simpleDescription: String = "A simple structure"
mutating func adjust() {
simpleDescription += " (adjusted)"
}
}
var b = SimpleStructure()
b.adjust()
let bDescription = b.simpleDescription
extension Int: ExampleProtocol {
var simpleDescription: String {
return "The number \(self)"
}
mutating func adjust() {
self += 42
}
}
print(7.simpleDescription)
var seven = 7
seven.adjust()
let protocolValue: ExampleProtocol = a
print(protocolValue.simpleDescription)
// 异常
enum PrinterError: Error {
case outOfPaper
case noToner
case onFire
}
func send(job: Int, toPrinter printerName: String) throws -> String {
if printerName == "Never Has Toner" {
throw PrinterError.noToner
}
return " Job sent"
}
do {
let printerResponse = try send(job: 1040, toPrinter: "Never Has Toner")
print(printerResponse)
} catch PrinterError.onFire {
print("I'll just put this over here, with the rest of the fire")
} catch let printerError as PrinterError {
print("Printer error: \(printerError)")
} catch {
print(error)
}
let printerSuccess = try? send(job: 1884, toPrinter: "Mergenthaler")
let printerFailure = try? send(job: 1885, toPrinter: "Never Has Toner")
var fridgeIsOpen = false
let fridgeContent = ["milk", "eggs", "leftovers"]
func fridgeContains(food: String) -> Bool {
fridgeIsOpen = true
defer {
fridgeIsOpen = false
}
let result = fridgeContent.contains(food)
return result
}
fridgeContains(food: "banana")
print(fridgeIsOpen)
func makeArray- (repeating item: Item, numberOfTimes: Int) -> [Item] {
var result = [Item]()
for _ in 0 ..< numberOfTimes {
result.append(item)
}
return result
}
makeArray(repeating: "knock", numberOfTimes: 4)
enum OptionalValue {
case none
case some(Wrapped)
}
var possibleInteger: OptionalValue = .none
possibleInteger = .some(100)
func anyCommonElements(lhs: T, _ rhs: U) -> Bool where T.Iterator.Element: Equatable, T.Iterator.Element == U.Iterator.Element {
for lhsItem in lhs {
for rhsItem in rhs {
if lhsItem == rhsItem {
return true
}
}
}
return false
}
anyCommonElements(lhs: [1, 2, 3], [3])
let minValue = Int16.min
let maxValue = UInt8.max
let justOverOneMillion = 1_000_000.000_000_1
typealias AudioSample = UInt16
var maxAmplitudeFound = AudioSample.min
let http404Error = (404, "Not Found")
let possibleString: String? = "An optional string."
let forcedString: String = possibleString!
let assumedString: String! = "An implicitly unwrapped optional string."
let implicitString: String = assumedString
