Swift

var score = 0  // Variable
let pi = 3.14  // Constant

var greeting = "Hello"
var numberOfToys = 8
var isMorning = true

var numberOfToys: Int = 8
numberOfToys += 1

print(numberOfToys)
// prints "9"

var greeting: String = "Hello"
var numberOfToys: Int = 8
var isMorning: Bool = true
var price: Double = 8.99

var x = 0
x = 4 + 2 // x is now 6
x = 4 - 2 // x is now 2
x = 4 * 2 // x is now 8
x = 4 / 2 // x is now 2
x = 4 % 2 // x is now 0

var numberOfDogs = 100
numberOfDogs += 1
print("There are \(numberOfDogs) Dalmatians!")

// print: There are 101 Dalmatians!

var apples = 6
print("I have \(apples) apples!")

// print: I have 6 apples!

let myLongString = """
Swift?
This is my favorite language!
Yeah!
"""

// This line represents a comment in Swift.

/*
This is all commented out.
None will run!
*/

let player = ("Maya", 5, 150)

print(player) // ("Maya", 5, 150)
print("\(player.0): level \(player.1), \(player.2) pts") // Maya: level 5, 150 pts

let player = (name: "Maya", level: 5)
let (currentName, curLevel) = player
print("\(currentName): level \(curLevel)")
// print: Maya: level 5

// MARK: -view settings

// TODO: update logic to accommodate data changes

// FIXME: Fix buggy behavior when making changes to existing entries

var greeting = "Hello"
var numberOfToys = 8
var isMorning = true

var greeting: String = "Hello"
var numberOfToys: Int = 8
var isMorning: Bool = true

var numberOfToys: Int = 8
numberOfToys += 1

print(numberOfToys)
// print "9"

let greeting = "Hello"
let numberOfToys = 8
let isMorning = true

let greeting: String = "Hello"
let numberOfToys: Int = 8
let isMorning: Bool = true

let numberOfToys: Int = 8
numberOfToys += 1
// Error: numberOfToys is immutable

import Foundation

let df = DateFormatter()
df.dateFormat = "d MMMM yyyy"

guard var birth = df.date(from: "5 June 1999") else {
    print("Date is not valid")
    return
}

var age: Int {
    Calendar.current
        .dateComponents([.year],
                        from: birth,
                        to: Date()).year!
}

print(age) // 23
guard let birth2 = df.date(from: "5 June 2002") else {
    print("Date is not valid")
    return
}
birth = birth2
print(age) // 20

var distanceInMeters: Float = 100

var distanceInFeet: Float {
  get {
    distanceInMeters *3.28
  }
  set(newDistance) {
    distanceInMeters = newDistance /3.28
  }
}

print(distanceInMeters) // 100.0
print(distanceInFeet)   // 328.0

distanceInFeet = 250
print(distanceInMeters) // 76.21951
print(distanceInFeet)   // 250.0

distanceInMeters = 800
print(distanceInMeters) // 800.0
print(distanceInFeet)   // 2624.0

var distance = 5 {
  willSet {
    print("The distance will be set")
  }
}

distance = 10 // print: distance will be set

var distance = 5 {
  willSet(newDistance) {
    print("The distance will be set \(newDistance)")
  }
}

distance = 10 // print: distance will be set to 10

var distance = 5 {
  didSet {
    print("The distance is set to \(distance)")
    print("Its old value is: \(oldValue)")
  }
}
distance = 10 // print: distance will be set to 10
              // print: its old value is: 5

var distance = 5 {
  willSet(newDistance) {
    print("The distance will be set to \(newDistance)")
  }
  didSet {
    print("The distance is set to \(distance)")
    print("Its old value is: \(oldValue)")
  }
}
distance = 10

var halloween = true
if halloween {
  print("Trick or treat!")
}
// print: Trick or treat!
if 5 > 3 {
  print("5 is greater than 3")
} else {
  print("5 is not more than 3")
}
// output: "5 is greater than 3"

var turbulence = false

if turbulence {
  print("Please sit down.")
} else {
  print("You are free to move around.")
}
// print: You are free to move around.

var weather = "rainy"
if weather == "sunny" {
  print("Get some sunscreen")
} else if weather == "rainy" {
  print("Take an umbrella")
} else if weather == "snowing" {
  print("Put on your snow boots")
} else {
  print("Invalid weather")
}
// print: take an umbrella

5 > 1      // true
6 < 10     // true
2 >= 3     // false
3 <= 5     // true
"A" == "a" // false
"B" != "b" // true

var driverLicense = true

driverLicense
    ? print("driver seat") : print("passenger seat")
// print: driver's seat

var secondaryColor = "green"

switch secondaryColor {
  case "orange":
    print("A mixture of red and yellow")
  case "purple":
    print("A mix of red and blue")
  default:
    print("This may not be a secondary color")
}
// print: mix of blue and yellow

let year = 1905
var artPeriod: String

switch year {
  case 1860...1885:
    artPeriod = "Impressionism"
  case 1886...1910:
    artPeriod = "Post-Impressionism"
  default:
    artPeriod = "Unknown"
}
// print: post-impressionism

let service = "Seamless"

switch service {
case "Uber", "Lyft":
    print("travel")
  case "DoorDash", "Seamless", "GrubHub":
    print("Restaurant delivery")
  case "Instacart", "FreshDirect":
    print("Grocery Delivery")
  default:
    print("Unknown service")
}
// print: restaurant takeaway

let num = 7

switch num {
  case let x where x % 2 == 0:
    print("\(num) is even")
  case let x where x % 2 == 1:
    print("\(num) odd number")
  default:
    print("\(num) is invalid")
}

// print: 7 odd

!true  // false
!false //true

true && true   // true
true && false  // false
false && true  // false
false && false // false

true || true   // true
true || false  // true
false || true  // true
false || false // false

!false && true || false // true

false || true && false // false

// without parentheses:
true || true && false || false
//----> true

// with brackets:
(true || true) && (false || false)
//----> false

func greet(name: String?) {
  guard let unwrapped = name else {
    print("Hello guest!")
    return
  }
  print("Hello \(unwrapped)!")
}
greet(name: "Asma") // output: Hello Asma!
greet(name: nil)    // output: Hello guest!

let zeroToThree = 0...3
//zeroToThree: 0, 1, 2, 3

for oddNum in stride(from: 1, to: 5, by: 2) {
  print(oddNum)
}
// print: 1
// print: 3

for char in "hehe" {
  print(char)
}
// print: h
// print: e
// print: h
// print: e

for num in 0...5 {
  if num % 2 == 0 {
    continue
  }
  print(num)
}
// print: 1
// print: 3
// print: 5

for char in "supercalifragilistic" {
if char == "c" {
    break
  }
  print(char)
}
// print: s
// print: u
// print: p
// print: e
// print: r

for _ in 1...3 {
  print("Ole")
}
// print: Ole
// print: Ole
// print: Ole

var counter = 1
var stopNum = Int. random(in: 1...10)

while counter < stopNum {
  print(counter)
  counter += 1
}
// loop to print until the stop condition is met

var scores = [Int]()
// array is empty: []

var grocery = ["🥓", "🥞", "🍪", "🥛", "🍊"]
print(grocery.count)
// print: 5

var vowels = ["a", "e", "i", "o", "u"]

print(vowels[0]) // prints: a
print(vowels[1]) // prints: e
print(vowels[2]) // print: i
print(vowels[3]) // prints: o
print(vowels[4]) // prints: u

// use type inference:
var snowfall = [2.4, 3.6, 3.4, 1.8, 0.0]
// explicit type:
var temp: [Int] = [33, 31, 30, 38, 44]

var gymBadges = ["Boulder", "Cascade"]
gymBadges.append("Thunder")
gymBadges += ["Rainbow", "Soul"]
// ["Boulder", "Cascade", "Thunder",
// "Rainbow", "Soul"]

var moon = ["🌖", "🌗", "🌘", "🌑"]
moon.insert("🌕", at: 0)
// ["🌕", "🌖", "🌗", "🌘", "🌑"]

moon. remove(at: 4)
// ["🌕", "🌖", "🌗", "🌘"]

var employees = ["Peter", "Denial", "Jame"]
for person in employees {
  print(person)
}
// print: Peter
// print: Denial
// print: Jam

var paintingsInMOMA: Set = [
  "The Dream",
  "The Starry Night",
  "The False Mirror"
]

var team = Set<String>()

print(team)
// print: [] 

var vowels: Set = ["a", "e", "i", "o","u"]

var cookieJar: Set = [
  "Chocolate Chip",
  "Oatmeal Raisin"
]
// add a new element
cookieJar.insert("Peanut Butter Chip")

var oddNumbers: Set = [1, 2, 3, 5]

// remove existing element
oddNumbers.remove(2)
// remove all elements
oddNumbers.removeAll()

var names: Set = ["Rosa", "Doug", "Waldo"]
print(names.contains("Lola")) // print: false

if names.contains("Waldo"){
  print("There's Waldo!")
} else {
  print("Where's Waldo?")
}
// print: There's Waldo!

var recipe: Set = ["Egg", "Flour", "Sugar"]

for ingredient in recipe {
  print ("Include \(ingredient) in the recipe")
}

var emptySet = Set<String>()
print(emptySet.isEmpty)     // print: true

var populatedSet: Set = [1, 2, 3]
print(populatedSet.isEmpty) // print: false

var band: Set = ["Peter", "Denial", "Jame"]

print("The band has \(band.count) players.")
// print: Band has 4 players.

var setA: Set = ["A", "B", "C", "D"]
var setB: Set = ["C", "D", "E", "F"]

var setC = setA.intersection(setB)
print(setC) // print: ["D", "C"]

var setA: Set = ["A", "B", "C", "D"]
var setB: Set = ["C", "D", "E", "F"]

var setC = setA.union(setB)
print(setC) 
// print: ["B", "A", "D", "F", "C", "E"]

var setA: Set = ["A", "B", "C", "D"]
var setB: Set = ["C", "D", "E", "F"]

var setC = setA.symmetricDifference(setB)
print(setC)
// print: ["B", "E", "F", "A"]

var setA: Set = ["A", "B", "C", "D"]
var setB: Set = ["C", "D"]

var setC = setA.subtracting(setB)
print(setC) 
// print: ["B", "A"]

var dictionaryName = [
  "Key1": "Value1",
  "Key2": "Value2",
  "Key3": "Value3"
]

var fruitStand = [
  "Coconuts": 12,
  "Pineapples": 12,
  "Papaya": 12
]

var numberOfSides = [
  "triangle": 3,
  "square": 4,
  "rectangle": 4
]

var employeeID = [
  "Hamlet": 1367,
  "Horatio": 8261,
  "Ophelia": 9318
]

// initializer syntax:
var yearlyFishPopulation = [Int: Int]()

// Empty dictionary literal syntax:
var yearlyBirdPopulation: [Int: Int] = [:]

var pronunciation = [
  "library": "lai·breh·ree",
  "apple": "a·pl"
]
// new key: "programming", new value: "prow gra"
pronunciation["programming"] = "prow·gra"

var bookShelf = [
  "Goodnight": "Margaret Wise Brown",
  "The BFG": "Roald Dahl",
  "Falling Up": "Shel Silverstein",
  "No, David!": "David Shannon"
]
// remove value by setting key to nil
bookShelf["The BFG"] = nil

// remove value using .removeValue()
bookShelf. removeValue(forKey: "Goodnight")

// remove all values
bookShelf. removeAll()

var change = [
  "Quarter": 0.29,
  "Dime": 0.15,
  "Nickel": 0.05
]

// Change the value using subscript syntax
change["Quarter"] = .25

// Change the value using .updateValue()
change. updateValue(.10, forKey: "Dime")

var bakery = [String:Int]()

// check if the dictionary is empty
print(bakery.isEmpty) // prints true
bakery["Cupcakes"] = 12
// check if the dictionary is empty
print(bakery.isEmpty) // print false

var fruitStand = [
  "Apples": 12,
  "Oranges", 17
]
print(fruitStand.count) // print: 2

var hex = [
  "red": "#ff0000",
  "yellow": "#ffff00",
  "blue": "#0000ff",
]

print("Blue hexadecimal code \(hex["blue"])")
// print: blue hex code Optional("#0000ff")

if let redHex = hex["red"] {
  print("red hexadecimal code \(redHex)")
}
// print: red hex code #ff0000

var emojiMeaning = [
  "🤔": "Thinking Face",
  "😪": "Sleepy Face",
  "😵": "Dizzy Face"
]
// loop through keys and values
for (emoji, meaning) in emojiMeaning {
  print("\(emoji) is called '\(meaning)Emoji'")
}
// iterate through keys only
for emoji in emojiMeaning. keys {
  print(emoji)
}
// iterate through values only
for meaning in emojiMeaning. values {
  print(meaning)
}

func washCar() -> Void {
  print("Soap")
  print("Scrub")
  print("Rinse")
  print("Dry")
}

func greetLearner() {
 print("Welcome to CheatSheets.zip!")
}
// function call:
greetLearner()
// print: Welcome to CheatSheets.zip!

let birthYear = 1994
var currentYear = 2020

func findAge() -> Int {
  return currentYear-birthYear
}

print(findAge()) // prints: 26

func convertFracToDec(numerator: Double, denominator: Double) -> Double {
  return numerator / denominator
}

let decimal = convertFracToDec(numerator: 1.0, denominator: 2.0)
print(decimal) // prints: 0.5

func findDiff(_ a: Int, b: Int) -> Int {
  return a -b
}

print(findDiff(6, b: 4)) // prints: 2

func smartphoneModel() -> (name: String, version: String, yearReleased: Int) {
  return ("iPhone", "8 Plus", 2017)
}
let phone = smartphoneModel()

print(phone.name)         // print: iPhone
print(phone.version)      // print: 8 Plus
print(phone.yearReleased) // print: 2017

func findSquarePerimet(side: Int) -> Int {
  return side *4
}

let perimeter = findSquarePerimet(side: 5)
print(perimeter) // print: 20

// Parameter: side
// Argument: 5

func nextTotalSolarEclipse() -> String {
  "April 8th, 2024 🌎"
}

print(nextTotalSolarEclipse())
// print: April 8th, 2024 🌎

func greet(person: String = "guest") {
  print("Hello \(person)")
}
greet() // Hello guest
greet(person: "Aliya") // Hello Aliya

var currentSeason = "Winter"

func season(month: Int, name: inout String) {
  switch month {
    case 1...2:
      name = "Winter ⛄️"
    case 3...6:
      name = "Spring 🌱"
    case 7...9:
      name = "Summer ⛱"
    case 10...11:
      name = "Autumn 🍂"
    default:
      name = "Unknown"
  }
}
season(month: 4, name: &currentSeason)

print(currentSeason) // Spring 🌱

func totalStudent(data: String...) -> Int {
  let numStudents = data.count
  return numStudents
}

print(totalStudent(data: "Denial", "Peter"))
// print: 2

func getFirstInitial(from name: String?) -> String? {
  return name?.first
}

struct Building {
  var address: String
  var floors: Int
  init(address: String, floors: Int) {
    self.address = address
    self. floors = floors
  }
}

struct Car {
  var numOfWheels = 4
  var topSpeed = 80
}

var reliantRobin = Car(numOfWheels: 3)

print(reliantRobin.numOfWheels) // prints: 3
print(reliantRobin.topSpeed)    // print: 80

struct Person {
  var name: String
  var age: Int

  init(name: String, age: Int) {
    self.name = name
    self. age = age
  }
}

// Person instance:
var morty = Person(name: "Peter", age: 14)

struct TV {
  var size: Int
  var type: String
  
  init(size: Int, type: String) {
    self.size = size
    self.type = type
  }
}

var newTV = TV(size: 65, type: "LED")

print(type(of: "abc")) // print: String
print(type(of: 123))   // print: 123

struct Menu {
  var menuItems = ["Fries", "Burgers"]
  mutating func addToMenu(dish: String) {
    self.menuItems.append(dish)
  }
}

var dinerMenu = Menu()
dinerMenu.addToMenu(dish: "Toast")
print(dinerMenu.menuItems)
// prints: ["Fries", "Burgers", "Toast"]

struct Dog {
  func bark() {
    print("Woof")
  }
}
let fido = Dog()
fido.bark() // prints: Woof

class Player {
  var name: String

  init(name: String) {
    self.name = name
  }
}

var player1 = Player(name: "Tomoko")
var player2 = player1
player2.name = "Isabella"

print(player1.name) // Isabella
print(player2.name) // Isabella

class Person {
  var name = ""
  var age = 0
}

var sonny = Person()
// sonny is now an instance of Person

class Fruit {
  var hasSeeds = true
  var color: String

  init(color: String) {
    self.color = color
  }
}

let apple = Fruit(color: "red")

var ferris = Student()

ferris.name = "Ferris Bueller"
ferris.year = 12
ferris.gpa = 3.81
ferris.honors = false

class BankAccount {
  var balance = 0.0
  func deposit(amount: Double) {
    balance += amount
  }
  func withdraw(amount: Double) {
    balance -= amount
  }
}

class SavingsAccount: BankAccount {
  varinterest = 0.0

  func addInterest() {
    let interest = balance *0.005
    self. deposit(amount: interest)
  }
}

class Student {
  var name: String
  var year: Int
  var gpa: Double
  var honors: Bool
}

class Student {
  var name = ""
  var gpa = 0.0
  var honors = false
}

struct Resolution {
  var width = 0
  var height = 0
}
class VideoMode {
  var resolution = Resolution()
  var interlaced = false
  var frameRate = 0.0
  var name: String?
}

let resolution = Resolution(width: 1920)
let someVideoMode = VideoMode()

enum Day {
  case monday
  case tuesday
  case wednesday
  case thursday
  case friday
  case saturday
  case sunday
}

let casualWorkday: Day = .friday

enum Dessert {
  case cake(flavor: String)
  case vanillaIceCream(scoops: Int)
  case brownie
}

let customerOrder: Dessert = .cake(flavor: "Red Velvet")
switch customerOrder {
  case let .cake(flavor):
    print("You ordered a \(flavor) cake")
  case .brownie:
    print("You ordered a chocolate cake")
}
// prints: "You ordered a red velvet cake"

enum Season: CaseIterable {
  case winter
  case spring
  case summer
  case falls
}

for season in Season.allCases {
  print(season)
}

enum Beatle: String {
  case john paul george ringo
}

print("The Beatles are \(Beatle.john.rawValue).")
// print: The Beatles are john.

enum Dessert {
  case cake(flavor: String)
  case vanillaIceCream(scoops: Int)
  case brownie
}

let order: Dessert = .cake(flavor: "Red Velvet")

enum Traffic {
  case light
  case heavy

  mutating func reportAccident() {
    self = .heavy
  }
}

var currentTraffic: Traffic = .light

currentTraffic. reportAccident()
// currentTraffic is now .heavy

enum Hello: String {
  case english = "Hello"
  case japanese = "Hello!"
  case emoji = "👋"
}
let hello1 = Hello(rawValue: "Hello!")
let hello2 = Hello(rawValue: "Привет")
print(hello1) // Optional(Hello.japanese)
print(hello2) // nil

enum ShirtSize: String {
  case small = "S"
  case medium = "M"
  case large = "L"
  case extraLarge = "XL"
  var description: String {
    return "The size of this shirt is \(self.rawValue)"
  }
}