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- mo betta examples
- add `inout` example - better `optional` example - Playground issue has been resolved, uncommented `protocol` example
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@ -13,6 +13,9 @@ The official [Swift Programming Language](https://itunes.apple.com/us/book/swift
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See also Apple's [getting started guide](https://developer.apple.com/library/prerelease/ios/referencelibrary/GettingStarted/LandingPage/index.html), which has a complete tutorial on Swift.
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```swift
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// import a module
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import UIKit
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//
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// MARK: Basics
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//
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@ -26,7 +29,7 @@ println("Hello, world")
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var myVariable = 42
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let øπΩ = "value" // unicode variable names
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let myConstant = 3.1415926
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let π = 3.1415926
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let convenience = "keyword" // contextual variable name
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let weak = "keyword"; let override = "another keyword" // statements can be separated by a semi-colon
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let `class` = "keyword" // backticks allow keywords to be used as variable names
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@ -34,9 +37,24 @@ let explicitDouble: Double = 70
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let intValue = 0007 // 7
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let largeIntValue = 77_000 // 77000
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let label = "some text " + String(myVariable) // Casting
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let piText = "Pi = \(myConstant), Pi 2 = \(myConstant * 2)" // String interpolation
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var optionalString: String? = "optional" // Can be nil
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optionalString = nil
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let piText = "Pi = \(π), Pi 2 = \(π * 2)" // String interpolation
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var someOptionalString: String? = "optional" // Can be nil
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if someOptionalString != nil {
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// I am not nil
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if someOptionalString!.hasPrefix("opt") {
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println("has the prefix")
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}
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let empty = someOptionalString?.isEmpty
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}
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someOptionalString = nil
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if let someStringConstant = someOptionalString {
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// has Some value
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}
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// AnyObject == id
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/*
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Comment here
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@ -84,9 +102,10 @@ for (key, value) in dict {
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}
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// for loop (range)
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for i in -1...1 { // [-1, 0, 1]
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for i in -1...shoppingList.count {
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println(i)
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}
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shoppingList[1...2] = ["steak", "peacons"]
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// use ..< to exclude the last number
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// while loop
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@ -123,14 +142,14 @@ default: // required (in order to cover all possible input)
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// Function with Swift header docs (format as reStructedText)
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/**
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A greet operation
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A greet operation
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- A bullet in docs
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- Another bullet in the docs
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- A bullet in docs
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- Another bullet in the docs
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:param: name A name
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:param: day A day
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:returns: A string containing the name and day value.
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:param: name A name
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:param: day A day
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:returns: A string containing the name and day value.
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*/
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func greet(name: String, day: String) -> String {
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return "Hello \(name), today is \(day)."
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@ -141,9 +160,16 @@ greet("Bob", "Tuesday")
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func getGasPrices() -> (Double, Double, Double) {
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return (3.59, 3.69, 3.79)
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}
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let pricesTuple = getGasPrices()
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let price = pricesTuple.2 // 3.79
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println("Gas price: \(price)")
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// Variadic Args
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func setup(numbers: Int...) {}
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func setup(numbers: Int...) {
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// its an array
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let number = numbers[0]
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let argCount = numbers.count
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}
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// Passing and returning functions
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func makeIncrementer() -> (Int -> Int) {
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@ -155,6 +181,17 @@ func makeIncrementer() -> (Int -> Int) {
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var increment = makeIncrementer()
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increment(7)
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// pass by ref
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func swapTwoInts(inout a: Int, inout b: Int) {
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let tempA = a
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a = b
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b = tempA
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}
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var someIntA = 7
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var someIntB = 3
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swapTwoInts(&someIntA, &someIntB)
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println(someIntB) // 7
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//
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// MARK: Closures
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@ -197,7 +234,7 @@ print(numbers) // [3, 6, 18]
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// Structures and classes have very similar capabilites
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struct NamesTable {
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let names: [String]
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// Custom subscript
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subscript(index: Int) -> String {
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return names[index]
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@ -239,7 +276,7 @@ internal class Rect: Shape {
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sideLength = newValue / 4
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}
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}
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// Lazily load a property
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// subShape remains nil (uninitialized) until getter called
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lazy var subShape = Rect(sideLength: 4)
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@ -255,8 +292,9 @@ internal class Rect: Shape {
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}
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init(sideLength: Int) {
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super.init()
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self.sideLength = sideLength
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// always super.init last when init custom properties
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super.init()
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}
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func shrink() {
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@ -313,7 +351,7 @@ enum Suit {
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//
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// `protocol`s can require that conforming types have specific
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// instance properties, instance methods, type methods,
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// instance properties, instance methods, type methods,
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// operators, and subscripts.
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protocol ShapeGenerator {
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@ -321,7 +359,6 @@ protocol ShapeGenerator {
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func buildShape() -> Shape
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}
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/*
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// Protocols declared with @objc allow optional functions,
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// which allow you to check for conformance
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@objc protocol TransformShape {
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@ -331,17 +368,17 @@ protocol ShapeGenerator {
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class MyShape: Rect {
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var delegate: TransformShape?
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func grow() {
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sideLength += 2
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if let allow = self.delegate?.canReshape?() {
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// test for delegate then for method
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self.delegate?.reshaped?()
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}
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}
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}
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*/
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//
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// MARK: Other
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@ -363,7 +400,7 @@ extension Int {
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var customProperty: String {
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return "This is \(self)"
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}
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func multiplyBy(num: Int) -> Int {
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return num * self
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}
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@ -372,7 +409,7 @@ extension Int {
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println(7.customProperty) // "This is 7"
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println(14.multiplyBy(2)) // 42
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// Generics: Similar to Java. Use the `where` keyword to specify the
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// Generics: Similar to Java and C#. Use the `where` keyword to specify the
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// requirements of the generics.
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func findIndex<T: Equatable>(array: [T], valueToFind: T) -> Int? {
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