敲敲打打，

每天差不多一个小时来学这个，

相信到时候再用XCODE，感觉会熟悉很多。。

class Counter {	var count = 0	func increment() {		count += 1	}	func increment(by amount: Int) {		count += amount	}	func reset() {		count = 0	}}let counter = Counter()counter.increment()print(counter.count)print(counter.increment(by: 5))print(counter.reset())class Vehicle {	var currentSpeed = 0.0	var description: String {		return "traveling at \(currentSpeed) miles per hour"	}	func makeNoise() {		//nothing	}}class Bicycle: Vehicle {	var hasBasket = false}let bicycle = Bicycle()bicycle.hasBasket = truebicycle.currentSpeed = 15.0print("Bicycle: \(bicycle.description)")let someVehicle = Vehicle()print("Vehicle: \(someVehicle.description)")struct Fahrenheit {	var temperature: Double	init() {		temperature = 32.0	}}var f = Fahrenheit()print("The default temperature is \(f.temperature) Fahrenheit")struct Color {	let red, green, blue: Double	init(red: Double, green: Double, blue: Double) {		self.red = red		self.green = green		self.blue = blue	}		init(white: Double) {		red = white		green = white		blue = white	}}let magenta = Color(red: 1.0, green: 0.0, blue: 1.0)let halfGray = Color(white: 0.5)print(magenta.red)print(halfGray.red)class Bank {	static var coinsInBank = 10_000	static func distribute(coins numberOfCoinsRequested: Int) -> Int {		let numberOfCoinsToVend = min(numberOfCoinsRequested, coinsInBank)		coinsInBank -= numberOfCoinsToVend		return numberOfCoinsToVend	}	static func receive(coins: Int) {		coinsInBank += coins	}}class Player {	var coinsInPurse: Int	init(coins: Int) {		coinsInPurse = Bank.distribute(coins: coins)	}		func win(coins: Int) {		coinsInPurse += Bank.distribute(coins: coins)	}	deinit {		Bank.receive(coins: coinsInPurse)	}}var playerOne: Player? = Player(coins: 100)print("A new player has joined the game with \(playerOne!.coinsInPurse) coins")